When the UK leaves the EU on 31 January, it will no longer have representation in EU decision-making. The 73 UK MEPs will vacate their seats in the European Parliament (EP). Some of their seats will be taken up by new MEPs from the remaining 27 EU Member States.  

This Insight explains the background to this reallocation of seats, and its impact on the relative strength of political groups within the European Parliament.

The reallocation of European Parliament seats 

The EU adopted legislation in June 2018 reallocating some of the UK’s seats in the European Parliament to other Member States.

27 of the UK’s seats will be redistributed to 14 other EU Member States. The reallocation was aimed at addressing underrepresentation by MEPs in these States.

The remaining 46 UK seats will be set aside for future allocations should new Member States join the EU. This will also help to keep the number of MEPs below the cap of 751 set by the EU Treaties should the EU expand further. In the meantime, the EP will be reduced in size to 705 MEPs.   

The biggest gainers from the new seat allocation will be Spain and France with five additional seats each. Italy and the Netherlands get three additional seats each. Ireland gets an additional two seats, and nine other Member States will get one extra seat each (see table below).

The 2019 European Parliament elections

The original intention was that this new allocation would take effect at the May 2019 European Parliament elections, as the UK was expected to have left the EU by then. But extensions to the Article 50 period meant that the UK ended up participating in these elections.

The legislation provided that in the event of the UK still being a Member State at the beginning of the new parliamentary term, the previous allocation would continue to apply. Once the UK’s withdrawal from the EU became legally effective, the new allocation would kick in.

To enable the reallocation, reserve MEPs were elected  in the 14 Member States that were due to get extra seats.  In those Member States the 2019 EP elections were organised as if the new allocation was in place. But the MEPs elected to the additional seats allocated after Brexit would not be able to take up their seats until the UK left the EU.

Impact on the size of political groups in the European Parliament

Most MEPs in the European Parliament sit in political groups organised across pan-European lines. In June, the Library published an explanation of these political groups and their formation.

The table below shows how many MEPs each political group will lose when the UK leaves and the MEPs they will gain from the new intake.

This Table shows the distribution of MEPs (by country and by Political group) in the European Parliament pre and post Brexit.

The European Parliament’s figures currently indicate there are only 750 MEPs. This is because the imprisoned Catalan MEP, Oriol Junqueras, has not been able to take up his seat. The EP has asked the Spanish authorities for a replacement for him. Mr Junqueras is the President of the European Free Alliance and would join the Greens/EFA group if allowed to take up his seat. His replacement would also most likely join this group.

The biggest loss of MEPs comes in the non-attached (NI) category. These are MEPs that do not belong to any political group. 24 Brexit Party MEPs, one (formerly Brexit Party) independent and the one Democratic Unionist Party MEP in this category will vacate their seats. 29 Brexit Party MEPs were elected in 2019, but four of these have since joined the Conservative Party.  

The political group losing the most UK MEPs is the Renew Europe (RE) group. It will lose its 16 Liberal Democrat MEPs, and one from the Alliance Party of Northern Ireland. The Greens/European Free Alliance loses 11 MEPs: seven from the Green Party, three from the Scottish National Party (SNP) and one from Plaid Cymru.

The SNP MEP Heather Anderson will be an MEP for only four days. She was approved as a replacement for Alyn Smith on 28 January after Mr Smith was elected as an MP in the December 2019 General Election. Under EU law MEPs cannot also be members of national parliaments.

The Socialists & Democrats (S&D) group loses 10 Labour Party MEPs. However, in gaining four new MEPs it actually increases its proportional size given the decrease in the size of the EP.

The European Conservatives and Reformists (ECR) group also loses MEPs but remains about the same in terms of proportional strength. The ECR group suffers a greater loss than it would have if Brexit had taken place in October 2019. This is because of the four Brexit Party MEPs who have since quit the party and joined the four existing Conservative Party MEPs in the group.     

The United Left/Nordic Green (GUE/NGL) also gains in proportional size. It loses its one Northern Ireland Sinn Féin MEP without gaining any new MEPs.

The chart below shows the change in size for each political group following Brexit.

The graph shows the membership of the European Parliament. It shows both the number of seats and the proportion of seats by political group.

Impact on the balance of power in the European Parliament

The biggest gains will be made by the two political groups that do not have any UK MEPs to lose. These are the centre-right European People’s Party (EPP) Group, which gains five MEPs, and the far right populist Identity and Democracy (ID) group which gains three MEPs. The ID group will overtake the Greens/EFA as the fourth largest group in the EP.

The chart below shows how this changing political group size affects the balance between groups in the EP. The three largest groups are the EPP, S&D and RE. They are all largely in favour of the European integration process and have voted together on key decisions, such as the Parliament vote approving the new European Commission in November. These three groups between them have slightly increased their strength in the EP.

The shows two pie-charts displaying MEPs by political group before and after Brexit.

Further Reading

Political group formation in the European Parliament, House of Commons Library.

European Parliament elections 2019: results and analysis, House of Commons Library.

The European Parliament after Brexit, European Parliament Research Service.


About the authors: Stefano Fella is a senior researcher in international affairs and defence at the House of Commons Library, specialising in Brexit. Elise Uberoi specialises in social and general statistics at the House of Commons Library.


Photo credit: © European Union 2014 – European Parliament