Dutch polls have opened in elections for the European Parliament, starting four days of voting across the 28-nation bloc that pits supporters of deeper integration against populist Euroskeptics who want more power for their national governments.

A half hour after voting started in the Netherlands, polls open across the United Kingdom, the only other country voting Thursday, and a nation still wrestling with its plans to leave the European Union altogether and the leadership of embattled Prime Minister Theresa May.

The elections, which end Sunday night, come as support is surging for populists and nationalists who want to rein in the EU's powers, while traditional powerhouses like France and Germany insist that unity is the best buffer against the shifting economic and security interests of an emerging new world order.