BRUSSELS (AP) — The traditional centrist leaders of Europe have been assailed from the nationalist, anti-immigration far-right and the environmental activist left in polarized, continentwide elections that will force pro-European moderates into forging new alliances.

The main issue uniting those occupying Europe's center ground is their refusal to work with far-right groups whose ranks are made up of nationalist parties led by the likes of Matteo Salvini in Italy and Marine Le Pen in France, whose parties celebrated landmark triumphs from four days of voting for the 751-seat European Parliament.

Manfred Weber is leader of the center-right EPP, which lost 36 seats but remains the largest group in the legislature. He says that "from now on those who want to have a strong European Union have to join forces."