Conservative parties decisively beat Socialists in the EU parliamentary elections, marred by a new record low turnout.

Europe's left failed to capitalise on widespread concerns over the recession and far-right anti-immigrant and euro-sceptic parties seized on the void to gain support for their hardline message.

Socialist parties in power in Britain, Spain and Portugal were punished by their electorates while other left wing parties in opposition in Germany and France suffered painful losses.

The centre-right European People's Party secured 267-271 seats, making it the biggest group in the 736-member assembly, ahead of the Socialists on 157-161 seats, according to official estimates.

The result gives the EPP nearly as many lawmakers as they had in the last parliament, which had 785 seats. The strong showing also comes despite the British and Czech conservatives deserting the group.

The Liberal Democrats came in third with 80-82 seats followed by the Greens with 53 seats in the parliament, the European Union's only directly elected institution.

Some 388 million people were eligible to vote in the world's biggest transnational elections, ended on Sunday, which were spread over four days.

Turnout slumped to 43.4 per cent, down from 45.5 per cent in 2004.