Surveys predict Europe's far right will surge in EU elections next month, giving it more influence in Brussels politics even if mainstream players still have greater weight.

Some 370 million voters are being called to cast ballots in the European Union's 27 countries from June 6 to 9 to select the 720 lawmakers who will sit in the next European Parliament.

While voter-intention polls point to inroads by radical-right parties, the mainstream in the parliament — made up of three groups: the center-right EPP, the left-leaning Socialists and Democrats, and the centrist Renew Europe — is still expected to end up ahead.