BRUSSELS – Voters are expected to cast ballots in record numbers across the European Union’s 27 member states over four days from Thursday, when polls open for the European Parliament elections.

However, the high turnout is unlikely to be a mark of approval for the EU in its current form. Opinion polls suggest a surge of support for far-right and Eurosceptic parties, potentially signalling a political earthquake that could reverberate around the world, and have implications for the UK.

A European Parliament that shifts significantly to the right would be less inclined to co-operate. “As the UK knows all too well, a right-wing government is an inward-looking government,” says Rebecca Christie, a senior fellow at Bruegel, a Brussels-based think-tank. “Since Brexit, the EU already is consulting the UK a lot less on pretty much everything.

“And if the EU really becomes consumed with a lot of these European values battles, and tugs-of-war between the centre and, say Viktor Orban in Hungary, the UK is just going to fade out.”

Turmoil in the EU could complicate negotiations and partnerships on anything from immigration to trade to security.

EuropeElects, which compiles national polls, predicts that far-right parties could win up to a third of the parliament’s 720 seats, up by a third since the last elections in 2019. The European Council on Foreign Relations (ECFR) think-tank forecasts that Eurosceptic populists will top the polls in nine EU nations – including Austria, Belgium, France and the Netherlands – and will come second or third in a further nine countries.

They are unlikely to dominate the next parliament, but they could disrupt and derail the EU’s legislative agenda over the next five years, including the next round of climate change laws and foreign policy.

A January report by US think-tank the Atlantic Council stated that “more co–operation is needed” between the UK and EU on climate, adding that “an EU-UK partnership based on accelerating the clean energy transition would be a logical step forward”.

“The vital question is whether the centre holds. Or will the extremes disrupt it and prevent us from moving forward,” says Seán Kelly, an Irish MEP from Fine Gael, part of the European People’s Party (EPP) group.

“Decision-making has always been difficult, but it could become even harder. The far right won’t be able to control matters, but they could hold things up. And it could have serious implications for financing the war in Ukraine and financing the Green Deal.”

The rise of the far right in Europe could be significant for Ukraine, currently facing a renewed Russian onslaught, and desperately seeking more arms and aid: many far-right MEPs have questioned whether the EU should be supporting Kyiv, and some have even openly advocated victory for Russia.

The UK has played a vital role in the Western response as Russia’s invasion motivated renewed co-operation across Europe, according to academics writing for Engage, a project that examines challenges to global governance.

They warned that if the US votes for another Trump administration, UK and EU leadership will be “even more critical to maintaining and co-ordinating Western efforts” – and that if populist representation increases in the Europe, Britain’s role will be “appreciated even more in European capitals where populist government do not hold sway”.

Former UK national security adviser Peter Ricketts recently observed in Politico that “any shift in the bloc’s foreign policy will inevitably have implications for the UK’s national security“, but said the EU and UK had generally been aligned on key issues to date.

Fabian Zuleeg, chief executive of the European Policy Centre (EPC), expects relations between Britain and the EU to improve with a new government in London in July, and does not think the European election will have a major impact.

However, he suggests a strong result from the far right could inspire nationalist politicians in the UK, like Nigel Farage’s Reform Party. “There will certainly be a narrative from the far right in the UK that the strong showing in the elections is a sign that European populations are looking for a different Europe,” he said.

The political shift comes amid widespread voter unease across Europe amid turbulence from the pandemic to the wars in Ukraine and the Middle East, with mainstream parties struggling to project stable leadership. The rise of far-right populist figures such as Geert Wilders in the Netherlands, Marine Le Pen in France, Orban in Hungary and Giorgia Meloni in Italy reflects a growing disenchantment with the EU’s handling of issues like migration.

Mr Wilders, who triumphed in last year’s Dutch election with a strongly anti-immigration message, is now expected to be the power behind the incoming coalition government in the Netherlands. Ms Meloni’s Brothers of Italy has a comfortable lead in the polls. Ms Le Pen’s far-right Rassemblement National is leading the polls with a third of the vote, more than double that of President Emmanuel Macron’s party, the LREM. The extremist Alternative for Germany (AfD) is polling higher than all the parties in Germany’s ruling coalition.

For the far right, this is about realigning the EU away from what it sees as a centralising bureaucracy and reverting to traditional values. “Europe is at a crossroads and these European elections represent the choice of the path we want to take for our future,” Susanna Ceccardi, an MEP with Italy’s hard-right Lega party, tells i. “We want to build a Europe of sovereign, free and strong nations that make Europe stronger, a Europe of peoples and territories that cultivate their roots, traditions and cultural identity.”

Ms Ceccardi says there is a reaction against the mainstream political groups, who have upheld the agenda of Ursula von der Leyen, the conservative president of the European Commission. “There are those who would like the United States of Europe, a centralising superstate that eliminates the differences between peoples and propagates cancel culture, woke ideology, false multiculturalism and eco-terrorism. It is the Europe of bureaucrats, of elites that no one has elected,” she said.

If combined, far-right parties could become the biggest force in the assembly, ahead of the mainstream political groups, the conservative EPP, the centre-left Socialists and Democrats (S&D) and the liberal Renew group.

A key issue after the elections will be how the parties align themselves. Far-right parties in the European Parliament have often descended into internecine squabbles, and they are currently split into three political factions, although there are attempts to create a broad nationalist alliance.

In a sign that the political centre has already shifted to the right, Ms Von der Leyen is also attempting to bring Ms Meloni into the conservative EPP group. It is a risky strategy. Although EU leaders are expected to reappoint Ms Von der Leyen as Commission president in July, she has been warned by the powerful centre-left S&D group and the Greens that they could sink her confirmation vote in the parliament.

Europe is about to make a vital choice on its future – and where it heads will matter for Britain.