Can Parliament stop Brexit?

What has to happen to stop Brexit?

Whether Parliament can “stop Brexit” is ultimately a political question. Neither the European Union (Withdrawal) Act 2018 nor the European Union (Notification of Withdrawal) Act 2017 provides Parliament with a domestic legal mechanism by which it can halt or revoke the Article 50 process.

Unless and until we know whether, as a matter of EU law, Article 50 is (unilaterally) revocable, we cannot say with any degree of confidence what Parliament’s role could/would have to be in the domestic process of making a revocation. The EU law question has been referred to the CJEU by the Inner House of the Court of Session in Scotland, following the case of Wightman v Secretary of State for Exiting the EU earlier this year. However, the UK Government is seeking leave to appeal that decision in the Scottish courts before the reference is actually heard by the CJEU later this month. We would only learn of Parliament’s role in that (e.g. whether a revocation requires primary legislation) if and when the matter returns to the Scottish courts.

Although Parliament can inhibit the ratification of any withdrawal agreement, it cannot legally “instruct” the Government to conduct foreign affairs or treaty negotiations in a certain way. This is because those matters fall under the Royal Prerogative. Even if Parliament approves a motion “directing” the Government to do something (such as to ask for an Article 50 extension or a second referendum) it cannot compel the Government to do those things. Motions have purely political force unless a statute provides otherwise. Ultimately, however, a Government holds its position and exercises powers under the prerogative because it commands the confidence of the House of Commons.

If we were to have a second referendum when is the earliest it could take place? Would that be too late?

In short, there is no definitive answer to this and in part it would depend on the politics of what unfolds in the next few weeks. Recent work by the UCL Constitution Unit has estimated that the minimum period between announcing the intention to legislate for a referendum and polling day would be about 22 weeks.[1] The Unit’s report is available on its website and the main points are summarised in their blog article: How long would it take to hold a second referendum on Brexit?

At the time of writing we are less than 19 weeks from Brexit day. The Prime Minister has repeatedly stated the Government will not make provision for a second referendum and will not revoke Article 50.

There has been speculation that Parliament could vote to force the Government to hold a second referendum, either by amending the motion on the meaningful vote on the Withdrawal Agreement or by amending the Government Bill expected to be introduced to implement any final Withdrawal Agreement in domestic law (if Parliament approves the draft agreement).

Some commentators have suggested that if the UK were to decide to hold a second referendum then this would require an extension to the two-year Article 50 window. This is the window that ends on 29 March 2019, when the UK is due to leave the EU. An extension to the Article 50 period would require unanimous approval by the EU27. Other commentators have suggested that the UK could reverse the Article 50 statement of intention to withdraw from the EU while the Government and Parliament consider their next steps.

There are certain things that are required before a UK-wide referendum can be held:

  • Legislation to allow for a referendum to be held - an Act of Parliament is required to allow for a referendum to take place
  • The Electoral Commission has a statutory duty to assess a question included in a Bill allowing for a referendum.
  • Practical preparation for the poll – the Government must make detailed conduct rules to apply aspects of electoral law, the Electoral Commission will need to prepare for the declaration of the national result and counting officer will need to arrange for the provision of polling stations, ballot papers, staff and count venues.
  • There is a statutory 10-week campaign period which includes designation of lead campaign groups.

Source: UCL report, page 14


There are some aspects of the regulation of referendums that are already in place as a result of the Political Parties, Elections and Referendums Act 2000 (PPERA), as amended. This regulates general aspects such as financial regulation of the campaign, designation of lead campaigns and statutory responsibilities of the Electoral Commission.

However, separate legislation is required to allow for a specific referendum to be held. This must be done by passing a Bill in Parliament. The Bill would need to include important provisions such as the franchise to be used, the question to asked in the referendum and the date of the poll. Detailed legislation to allow for the conduct of the poll is also required. This is normally in the form of a statutory instrument made under powers granted in the enabling Act.

The timing of the passage of a Bill will be influenced by a number of things. The Standing Orders of the House of Commons do not prescribe the timings of parliamentary stages of a bill and the length of time for a bill to pass through both Houses of Parliament and gain Royal Assent varies considerably.

How quickly a Government Bill proceeds through Parliament will partly depend on the length and complexity of the Bill, how many amendments are tabled, whether the Bill has broad cross-party support or whether it is controversial. It will also depend on whether the Bill seeks to change the regulatory framework for referendums. There have been several reports and recommendations on improving the regulation of referendums recently. Trying to incorporate regulatory modifications in the Bill could make the Bill more complex and add to the time taken to scrutinise the Bill.

Bills can be programmed in the House of Commons, the Government can control the timetable of proceedings on Bills, but this requires a programme motion to be passed by the House. There are no equivalent programming provisions in the House of Lords and a controversial Bill could take considerably longer in the Lords.

One important aspect of the timing is the statutory responsibility of the Electoral Commission to assess the intelligibility of the question included in the Bill, see below.

Emergency legislation is sometimes passed quickly if both Houses accelerate their normal procedure. However, given the Government is opposed to a second referendum, this currently seems unlikely.

Question testing

The Electoral Commission has a statutory duty to assess any question to be put in a referendum. The way the Commission assesses a question is not set out in legislation and it can consider the wording ‘in such a manner as they may determine’.[2] In recent assessments the Electoral Commission has taken about 12 weeks.

The UCL Constitution Unit report suggests that the Commission could decide to truncate its assessment of the question or that Parliament could decide to pass referendum legislation, including the proposed question, without waiting for the Commission’s assessment. However, the report goes on to point out the risks to the perceived fairness of the referendum of ignoring Electoral Commission advice. In addition, there is currently little consensus about how any question should be phrased, or whether it should be simple ‘yes’/’no’ question or some sort of multipart or two stage question:

  1. In the current polarised political environment over Brexit it is of utmost importance that that the result of any referendum should be perceived as legitimate. Integral to this is public confidence in the neutrality and intelligibility of the question. Curtailing or abandoning the normal process could jeopardise this, and risk accusations that the question was misleading or biased. Furthermore…there is a possibility that the referendum question could take a form not previously used in the UK – with the likeliest innovation being a three option question. This would necessitate particularly careful testing. Therefore, it is likely that something similar to the usual process, albeit perhaps on a somewhat condensed timetable, will be necessary.[3]

Practical preparation

Any poll will need practical preparation. If there is a serious possibility of a referendum Bill making progress some of this preparation can be done in advance. As the 2017 snap general election showed it is possible to organise some practical aspects of a poll at short notice.

However, in order for the poll to take place the Government needs to produce detailed conduct rules. These could be based on the detailed rules used to the 2016 referendum, the European Union Referendum (Conduct) Regulations 2016 . These were issued four months before the 2016 poll. In the UCL Constitution report it comments that if the rules for a referendum were largely the same as in previous votes then it could be possible to issue these close to the start of the statutory 10 week pre-referendum period (see below) but that “significant rule changes, or an innovative format such as a multi-option question, would increase pressure to allow more time.”[4]

Statutory pre-referendum period

There is a minimum campaign period for referendums held under the framework set out in Political Parties, Elections and Referendums Act. This must be 10 weeks and comprises three stages. The first four weeks is the four-week period for campaigners to apply to be the lead campaign groups. The next two weeks are the period in which the Commission assesses applications to be lead campaign groups for each possible outcome and designates those groups.

On designation of lead campaign groups, the UCL Constitution Unit comments:

  1. If there is more than one suitable applicant to be lead campaigner for one outcome, it would be difficult for the Electoral Commission to designate in less than two weeks. This choice is unavoidably controversial, and subject to potential judicial review. It must be made in a demonstrably fair and rigorous manner.[5]

This period cannot start until all other aspects of the referendum is known and the detailed conduct rules for a referendum have been put in place. Changes to this statutory period would require primary legislation.

If we were to remain as members of the EU would it be on the same terms as 2016? Also, would we pay the same money?

Whether the UK continues to contribute to the EU Budget as it currently does depends on the process by which the UK remains.

If the UK simply remains a Member State, with no break in its membership and no changes to the EU’s laws (presumably by unilaterally revoking Article 50) then it would continue to contribute to the EU Budget as it currently does. In this scenario, any changes that the EU would like to make to how its budget is funded would require the UK’s approval. This is because the EU regulation determining how the EU Budget is funded – the own resources decision (ORD) – can only be altered by unanimity and is in force without an expiry date. The ORD must also be ratified by a vote in the UK Parliament.

However, the ORD will be renegotiated for the 2021-2027 budget period, so it’s likely that there may be some changes to how Member States contribute, but the UK would have to agree to any changes.  

The situation is less clear if the UK remains but has to renegotiate its membership. How the UK contributes in this scenario will depend on the outcome of negotiations.

Current negotiations for 2021-2027

The EU is currently considering its next long-term spending plan – the multiannual financial framework 2021 – 2027. At the same time the EU is looking at how its budget will be funded, which is likely to lead to some revisions to the own resources decision, but, as I say above, any changes in the ORD requires agreement from each Member State. As section 3 of our briefing, A guide to the EU Budget , says, the European Commission has put out its proposals, but the European Council (made up of Member States’ heads of government) has yet to respond.

Can we legally reverse Article 50? Whose decision is that?

Article 50 TEU is silent on the matter of whether it can be revoked by the State that triggered it, and there are no judicial precedents to guide Court of Justice of the EU (CJEU) interpretation of Article 50. Academic opinion tends towards the conclusion that notification could be revoked before Brexit day,[6] but there have been some authoritative views to the contrary.[7] Ultimately, the question would have to be answered by the CJEU as it is a matter of EU law.

The question gives rise to others such as whether Article 50 could be revoked unilaterally or whether the EU Member States would have to give permission for the UK to revoke its notice, and how would they make that decision – by unanimity or qualified majority? Also, if it is revocable, would the UK remain an EU Member State on its existing terms (with opt-ins, opt-outs, budget rebate etc) or could the EU set conditions? There are reports that the UK Government’s legal advice was that Article 50 can be withdrawn, but the Government has not confirmed that it received such advice and maintains in any case that Article 50 will not be revoked as a matter of policy.

The UK Supreme Court did not address the matter of revocability in the Miller judgment because both parties had agreed to assume the notice was irrevocable, although many argued at the time that it would be the Supreme Court’s duty to refer the issue to the CJEU.[8]

In February 2018 a cross-party group of Members of the Scottish Parliament (from the Labour Party, SNP, Liberal Democrats and Scottish Greens), MEPs and MPs,[9] supported by the Good Law Project , were granted permission for judicial review into whether the UK could unilaterally revoke Article 50. The petitioners asked:

  1. Where a Member State has notified the European Council of its intention to withdraw from the European Union, does EU law permit that notice to be revoked unilaterally by the notifying Member State; and, if so, subject to what conditions and with what effect relative to the Member State remaining within the EU?

After an initial refusal to refer the question to the Court of Justice of the EU (CJEU) in June 2018,[10] an appeal in September resulted in the Scottish Court asking the CJEU for a preliminary ruling.

In early November the Government submitted written observations to the CJEU in Wightman and Others v Secretary of State for Exiting the European Union. Its position is that the questions are inadmissible because the CJEU does not answer hypothetical questions or provide advisory opinions. The Government also sought permission to appeal the decision of the Scottish Court to the Supreme Court, but its application failed.

The Government tried to persuade the Supreme Court to give it permission to appeal against the decision of the Inner House to refer the question to the CJEU. Permission has been refused because the Inner House judgment to refer to the CJEU is not a ‘final judgment’, so permission to appeal could not be sought directly from the Supreme Court; it is for Inner House to apply the CJEU ruling from the reference, so the matter still sits with them.

If the CJEU rules that unilateral revocability is permissible and the UK (somehow) decides to revoke its Article 50 notice, the UK’s opt-outs, opt-ins and budget rebate would probably be kept.  But the petitioners also asked about any “conditions” to revocation so their understanding of ‘unilateral’ is that it could involve the EU27 imposing limitations. If the CJEU says revocation is possible but conditional, on EU27 approval for example (i.e. not unilateral), or on changes to the UK’s various Treaty concessions (which could entail EU Treaty change), this would change the nature of the debate about the UK’s EU membership.

The oral hearing at the CJEU is due to take place on 27 November. The Good Law Project expects the ruling to be in late December but before Christmas.

[1]     UCL Constitution Unit, The Mechanics of a Further Referendum on Brexit , October 2018

[2]     Section 104 of the Political Parties, Elections and Referendums Act 20, as amended

[3]     UCL Constitution Unit, The Mechanics of a Further Referendum on Brexit , October 2018, p12-3

[4]     UCL Constitution Unit blog, How long would it take to hold a second referendum on Brexit?

[5]     UCL Constitution Unit, The Mechanics of a Further Referendum on Brexit , October 2018, p13

[6]     See, for example, UK Constitutional Law Association webpages on revocability issues.

[7]     See, for example, the March 2018 Report produced for the EP’s AFCO Committee, Verfassungsblog, Miller, Brexit and the (maybe not so evil) Court of Justice , Daniel Sarmiento, 8 November 2016.

[8]     See, for example, Peers , Syrpis , Sanchez-Graells , Sarmiento .

[9]     Andrew Wightman MSP, Ross Greer MSP, Alyn Smith MEP, David Martin MEP, Catherine Stihler MEP, Christine Jardine MP, Joanna Cherry QC MP.

[10]    Mainly because courts typically do not answer hypothetical questions and the CJEU has stated this principle in Gauweiler and others (Case C‑62/14, paras. 24 and 25).