The provisional results, released early on Friday, indicate support for pro-EU parties at the expense of the anti-EU vote.
If repeated on an EU-wide scale, it would confound earlier predictions of a huge influx of new members from so-called populist and nationalist parties.
However, a source with the Brexit party in the UK said it was “far too early” to make such forecasts, based solely on the exit polls from one Member State.
The Brexit party, headed by MEP Nigel Farage, is expected to easily win the majority of seats in the UK, trouncing the Tories and Labour with similar gains widely predicted for similar-minded political parties in other countries. The final results will be announced on Sunday night.
In the Netherlands, the Labour party of EU Commissioner Frans Timmermans is thought to have won a surprise victory when Dutch voters kicked off four days of voting across the EU.
An exit poll showed his party had easily seen off a Eurosceptic challenger who had been topping the polls. His party took 18 percent of the vote, double its 2014 performance.
Timmermans is the social democrat candidate for the Commission presidency and it is widely thought his candidacy may have had a positive impact on his party’s showing.
The far-right Forum for Democracy, led by nationalist Thierry Baudet, which had earlier been neck and neck in polls alongside Dutch Prime Minister Mark Rutte’s VVD1 finished third with 11 percent, the exit poll showed.
The Freedom Party of Geert Wilders, another Eurosceptic who has controversially campaigned against Islam, won just 4 percent, a decade low for the party.
"There is clearly a majority in the Netherlands that wants the European Union to continue to play a role” Frans Timmermans
The result will be seen as a disappointment for Wilders along with the pro-Nexit Forum for Democracy.
The Netherlands will have 26 seats in the new Parliament.
If the exit polling is proved correct, the results mean that Labour will win most seats, five, followed by Rutte's VVDl with four, Forum for Democracy taking three seats, the same as GroenLink.
Turnout was put at 42 percent, the highest in a European election in the country since 1989. The Dutch vote was a first test of the appeal in these elections of populist and Eurosceptic parties.
Reaction was swift with Forum for Democracy spokesman Derk Jan Eppink urging caution, saying, “I am always very careful with polls and the official results is not until Sunday, so we hope for an extra seat. Nevertheless, with three seats we can mean something in the European parliament.”
A clearly delighted Timmermans said, “There is clearly a majority in the Netherlands that wants the European Union to continue to play a role.”
“I realise that everywhere in Europe there is a need for another Europe, one that fights harder against climate change, that we have to cooperate on a social level, and where big business has to pay more taxes. I hope that this gives a tailwind for a lot of other social democrats in Europe.”
Ron Frensen, a Dutch TV commentator, said, however, that D66, which has a strong pro-EU message, had been squeezed between the “Frans Timmermans effect” and “in-fighting on the right.”
PvdA leader Lodewijk Asscher, meanwhile, said the exit poll prediction was “bizarre” while leading Dutch academic Sarah de Lange said the exit polls show “unexpected” gains for the social democrats and a smaller than predicted percentage for Thierry Baudet’s Forum.
Generally, far-right parties are expected to increase their standing across the EU but are still not expected to take more than a fifth of seats.
The anti-immigrant Alternative for Germany is forecast to win 12 percent, leaving it in fourth place, while Marine Le Pen’s National Rally leads opinion polls in France, slightly ahead of President Emmanuel Macron’s Republic On the Move party.
Elsewhere, an Ipsos MORI survey on voting intentions before the European elections commenced yesterday predicted that the Brexit Party will win the largest share of votes in the UK at 35 percent, followed by 20 percent for the Liberal Democrats, 15 percent for Labour, 10 percent for the Greens, 9 percent for the Conservatives, 3 percent for both UKIP and Change UK and 5 percent for other candidates.
Due to reporting restrictions, the results of the elections in the UK will not be announced until Sunday evening at the earliest.