Dutch voters have begun four days of voting across the European Union, with exit polls suggesting a tight race between a left-green alliance and the party of anti-Islam populist Geert Wilders.

Right-wing and far-right parties are widely expected to make big gains in many of the EU’s 27 member states, and that appears to have been borne out in the Netherlands, to an extent.

Although the Green-Labour alliance is set to take more seats in the European Parliament according to the exit poll, Mr Wilders’ Freedom Party is on course for big gains.

But he has not repeated the runaway victory of last November’s general election.

Under European law final results are not released until every country has voted, late on Sunday evening. Some 373 million Europeans are eligible to vote in the world’s second biggest democratic election after India.

The next European Parliament will have 720 seats, with each country having seats proportionate to their population. Germany will have 96, France 81 and Italy 76, while the Netherlands has 31.

The Dutch exit poll will be closely watched across Europe for potential trends that will emerge elsewhere on the continent, even though many voters tend to vote on national issues at least as much as on European policy.

Ireland and the Czech Republic vote on Friday, and the rest of the EU votes over the weekend.

A shift to the right has been widely expected in this election, with far-right parties eyeing victory in France, Belgium, Austria and Italy.

Their opponents are likely to take some satisfaction from Thursday night’s exit poll, because of the Green/Labour alliance’s performance. Geert Wilders’ party came first in Dutch national elections last November, and has secured a cabinet deal with three other parties, even though he will not be prime minister.

Any substantial shift to the right in the make-up of the European Parliament could affect EU policies on climate change, agriculture and potentially defence.

According to the Ipsos I&O poll of 20-30,000 Dutch voters at 35 polling stations, the Dutch centre-left alliance under former European Commissioner Frans Timmermans is on course to win eight seats, one more than Mr Wilders’ Freedom Party.

However, the margin of error is such that the race is too close to call. Turnout was estimated at almost 47%, a five-point rise on five years ago. Before the vote there had been talk of voter fatigue after months of wrangling over the formation of a new government.

Mr Wilders said he was delighted with the “nice result”. It was only an exit poll but it was clear that the Freedom Party was the big winner, he said, as his party had only one seat in the outgoing European Parliament. Another far-right party, which has been on the slide for months, is on course to lose all four of its seats.

The exit poll is an indication of just how polarised the Dutch vote has become, with a pro-European party in favour of climate change policies in the lead, closely followed by Mr Wilders, who wants less Europe and promises a government with “the strongest asylum policy ever”.

However, commentators pointed out that an estimated two-thirds of votes had been picked up by pro-EU parties, many of them centrist or liberal.

Migration and asylum was the most important factor for Dutch voters, according to Ipsos, and that is likely to reflected in much of the rest of Europe.

Voters the BBC spoke to at a variety of polling stations in The Hague on Thursday talked about security as well as the wars in Gaza and Ukraine. Many said a stronger EU was essential in the face of global insecurity.

While a quarter of Dutch voters said they were motivated by European politics, 21% said it was domestic politics, and 48% said it was a combination of the two.