Leading candidates in the European Union elections are gearing up for a final televised debate before millions of people take part in the world's biggest transnational polls on May 23-26.

The six candidates in the debate later Wednesday hail from mainstream parties and are vying for Jean-Claude Juncker's job as president of the European Commission, the powerful executive body that proposes EU laws and makes sure they are respected.

No populist or far-right politician is taking part in the debate, which starts at 1900 GMT (8 p.m. local time), even though they are expected to do well in the elections, particularly in Britain, France and Italy.

Some 400 million people are eligible to vote in the elections for the European Parliament but turnout is usually low.