How will Brexit affect European elections around the EU?

Not directly. Brexit barely features as an electoral issue in the rest of the bloc: as usual, voters will be swayed more by domestic politics and personal perceptions of the EU’s value. But it has influenced the debate indirectly.

Most European mainstream parties have become more explicitly pro-EU and hardly any of the nationalist parties calling for referendums on EU membership in 2016 are still doing so now, demanding instead an EU remodelled as a “Europe of nations”. Polls show the EU’s popularity is at a 30-year high.

Do the elections matter for the EU?

Yes. The 751-seat European parliament matters because along with the council of ministers – government members from all 28 countries – MEPs approve, amend or reject EU laws. They must also approve the new European Commission. The traditionally dominant centre-right (EPP) and centre-left (S&D) parliamentary groups are forecast to lose significant numbers of seats – and the majority they have held for 40 years. The liberals (ALDE) and Greens should be stronger, and the right-wing, EU-critical populists in Matteo Salvini and Marine Le Pen’s new European Alliance of People and Nations much stronger.

Majorities will be harder to form and less stable; nation-first parties seeking “less Europe” and more power for member states will have a greater influence on policy. At a time of many challenges for the EU – climate change, migration pressures, looming trade wars, eurozone reform, regional security, defiance of the rule of law in Hungary and Poland – this could be a complicating factor.

Yes. The European parliament has to sign off on the Brexit withdrawal agreement (assuming it is ever passed in Westminster). That could be problematic if the current stable majority, which has generally backed the European Commission’s Brexit approach, is disrupted by a large contingent of populist, EU-critical MEPs. The new parliament will also have a considerable say in the make-up of the new commission, which will eventually negotiate the EU’s future relationship with the UK. Finally, MEPs will have to agree the future relationship itself. In all of these areas a more divided, polarised and unstable European parliament with potentially conflicting demands could create significant problems for Britain.

What impact on the parliament might British MEPs have?

Even if they will be giving up their seats after Brexit, British MEPs could have a sizable impact on the new parliament over its five-year life. They could find themselves playing a critical role in selecting the new commission, which will be in place long after Britain has (in principle, at least) left the bloc. They will also be joining European parliamentary groups, which could determine how many policymaking posts, such as committee chairs, those groups have, how much speaking time they get and what their level of funding is. It is also possible, of course, that British MEPs will be called on to vote on legislation that could affect the UK’s future relationship with the EU.