Could Article 50 be extended to allow for a second Brexit referendum?

jess_sargent.000alan_renwick.000download.001With increasing speculation about a possible second referendum on Brexit, this is the fifth in a series of posts about the practicalities of such a poll. With ‘exit day’ set for 29 March 2019, Jess Sargeant, Alan Renwick and Meg Russell ask whether the Article 50 period could be extended to allow a referendum to take place, and what the knock-on consequences would be.

In a previous blogpost we concluded that, given the time it would take to hold a new referendum on Brexit, the UK’s exit day of 29 March 2019 would almost certainly need to be delayed. This is legally possible – Article 50, the clause of the EU treaty setting out the process by which member states can leave the EU, makes provision for an extension to the two-year period if agreed unanimously by the UK and the EU27. This post examines whether such an agreement is likely, what difficulties may be encountered should the UK’s leaving date be postponed, and what solutions could be found.

Would the EU be likely to agree an Article 50 extension?

All the indications are that the EU would be willing to agree an Article 50 extension to allow the UK to conduct a democratic process such as a general election or a referendum before Brexit is finalised. If remaining in the EU were an option in the referendum, the 27 might well want to afford the UK the opportunity to change its mind. Even if Remain were not an option, there is a strong argument that the EU would want to honour the democratic principles on which it was founded and not deny sufficient time for the UK electorate to have the chance to vote, provided it felt that the UK was being sincere and not just ‘playing for time’.

Would a UK parliamentary vote be required to extend Article 50?

The parliamentary authorisation for triggering Article 50 came through the EU (Notification of Withdrawal) Act 2018, which resulted from the Supreme Court’s ruling in the Miller case that parliamentary approval was needed for such a change. Subsequently the EU (Withdrawal) Act 2018 has defined exit day as 29 March 2019.

Therefore, it may be the case that parliament would need to consent to any extension of the Article 50 period. Whether or not parliamentary approval is strictly required in law, it would be politically prudent for the government to hold a parliamentary vote to authorise a request to extend Article 50. If there is a majority in parliament for a referendum, there would almost certainly be a majority also for extending the Article 50 window to allow one to take place. Any necessary legislative amendments could be included in the referendum legislation, so this is unlikely to add complexity.

Consequences of extending Article 50

Even if the UK asks for an Article 50 extension, and EU leaders are willing to support this, there are various complications that would flow from such a decision. Since Article 50 was first invoked, the EU27 have been proceeding on the basis that the UK would leave on 29 March 2019. Some changes have been put into effect in the expectation that this would happen, and these would need to be revisited.

The 2019 European Parliament elections

The European Parliament elections are scheduled to take place in all member states between 23 and 26 May 2019. On the assumption that the UK is leaving the EU, arrangements have been made for its seats to be reallocated. But if the UK remains in the EU at the time of the elections, EU treaty requirements would legally oblige the UK to take part. Nonetheless, holding MEP elections would cause problems for both the UK and the EU.

According to the EU’s arrangements, the reallocation of seats will not take place if the UK remains a member. This would cause inconvenience for those member states due to receive additional seats, which might require arrangements to be put in place to fill them should Brexit occur later. The sudden loss of 46 seats and reallocation of 27 others sometime after the elections, almost certainly resulting in a degree of political rebalancing, could potentially have some destabilising effects in the European Parliament. A second worry on the EU side is that UK participation in the MEP elections in controversial circumstances could result in election of a large number of Eurosceptic members, again with potentially destabilising effects, even if their presence is only temporary.

The bigger effect is the political impact that holding these elections could have in the UK itself. If Brexit were delayed, tensions would be running high, meaning that the European Parliament elections could become a kind of ‘proxy referendum’ with pro- and anti-EU blocs forming. While a referendum would be fought between campaign groups, the competitors in a European Parliament election would be political parties, but both major parties are currently divided on the issue. With the party system already under strain, such a ‘proxy referendum’ could even prove to be the catalyst for party splits. The proportional voting system used for the European Parliament would make it relatively easy for new groupings to break through electorally. Further, unlike in the 2016 referendum, EU citizens resident in the UK would be eligible to vote for UK MEPs, which could affect the result. Even leaving aside these political risks the elections would cost considerable public money and require action by parties, candidates, and voters themselves – all to elect MEPs who potentially would hold their seats for no more than a few weeks.

Could these difficulties by avoided?

One way out of these problems would be to hold a referendum before the European Parliament elections take place. Alternatively, if a referendum were held before MEPs took up their seats in July, this could avoid some but not all of the problems. Whether either of these is possible would depend on when a referendum was triggered – though in any scenario the timing is extremely tight.

Hence the question arises of whether the European Parliament elections could be avoided if the UK remains a member at the time that they are held. Any attempt to remove the UK’s formal legal obligation to hold these elections, through creating some kind of short-term exception, would require treaty change. Given the need for all member states to ratify any such amendment, this seems infeasible within the timescale.

Another option could be for the UK, with the EU’s tacit agreement, simply not to proceed with the elections, perhaps with a promise to hold them on some later date if the referendum reversed the Brexit decision. Whilst this might be a convenient political compromise, it would be legally problematic. Anyone eligible to vote in European Parliament elections in the UK could potentially launch a case with the European Court of Justice (ECJ), which would likely rule that elections should be held. In practice, by the time any such ruling was made, the UK might already have held the referendum and therefore be ready to take the appropriate action, making this a risk the government was willing to take. Nonetheless, it would be in breach of the treaty.

It may be suggested that current MEPs should be kept on to avoid holding elections. One mechanism that could be suggested for doing so is to give existing UK MEPs ‘observer status’ of a kind previously extended to new member states prior to joining the EU. However, this provision was specifically made in the accession treaties of these new states and so would not be available for the UK.

Implications for the EU budget, and for trade negotiations

It has already been agreed as part of the Brexit negotiations that the UK will continue to pay into the EU budget in 2019 and 2020, although this settlement will not be legally binding until the withdrawal agreement is ratified. Hence extending Article 50 would have no immediate implications for EU budgets. However, the EU27 have already begun the process of budget negotiation for the period post-2020, and continued uncertainty about the UK’s status could disrupt and delay those negotiations.

In addition, a significant delay of exit day would be likely to delay progress on negotiation of the UK’s future relationship with the EU, most importantly on any trade deal. It is intended that negotiations will be concluded within the transition period, which is due to end on the last day of the current EU’s seven-year budget period, 31 December 2020.

The 21-month transition period between March 2019 and December 2020 has already been widely criticised as too short to negotiate a trade deal. Any Article 50 extension would shorten this period further, so increasing the likelihood that transition would need to be extended. This would have further implications for the future EU budget.


Should the UK parliament decide to hold a second referendum on Brexit, it would almost certainly also support a delay to exit day should this prove necessary for the referendum to take place. The EU27 also look likely to agree to such an extension to facilitate a UK poll. Holding the European Parliament elections in the UK while such a referendum is pending is clearly undesirable for both the UK and the EU, but no easy solution exists. Should the UK remain a member when they are due, it will be for the government to weigh up the legal and political consequences and decide how to proceed.

The longer the Article 50 period is drawn out, and the uncertainty about the UK’s status remains, the greater the knock-on effect on other EU processes such as negotiations over the future EU budget and negotiations with the UK over a trade deal. The best solution would hence be to keep an extension to a minimum, and hold any referendum as soon as possible after 29 March. But this would depend both on the completion of key legal processes to facilitate a referendum, and on when and how such a referendum is triggered, as explored in previous posts. How these likely timelines fit together will be the subject of a future post.

This is the fifth in a series of posts on ‘The Mechanics of a Further Referendum on Brexit’. Further blogs on this topic will be added in the coming weeks: to see all posts in the series, visit our project page

About the authors

Jess Sargeant is a Research Assistant at the Constitution Unit. 

Alan Renwick is Deputy Director of the Constitution Unit.

Meg Russell is Director of the Constitution Unit.

6 thoughts on “Could Article 50 be extended to allow for a second Brexit referendum?

  1. There appears to be no legal basis for suspending Art 50 and the Council have no power to do so without making a structural change to The TFEU. Changes to the treaty require ratification by all member states which would likely be vetoed by the UK who at the moment is still a member of the EU. Suspension of Art 50 is just wishful thinking.

  2. Pingback: Brexit Highlights 17 – 23 September 2018 | Middle Temple Library Blog

  3. Pingback: Could Article 50 be extended to allow for a second Brexit referendum? (Constitution Unit) – BREXIT XXL

  4. could there be a referendum after uk leaves eu to rejoin following a few years of independence if it looked likely that a majority wished to rejoin the eu?

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