Over four days until Sunday, nearly 349 million Europeans in the newly enlarged EU are eligible to vote for the 732-member European Parliament.
Turned off by Brussels and focused on national issues, voters appear set to deliver protest votes to many leaders - if they can be bothered to turn out.
In Britain and the Netherlands, the only nations to vote on Thursday, electors showed little passion for European affairs as they cast ballots in a trickle from early morning.
"I was mostly thinking about my backyard today," said London cyclist Melanie Marwick, 27, for whom traffic is the big issue.
Amsterdam restaurant owner Fared Assarte - like many across Europe - was far more interested in the impending Euro 2004 soccer championship.
"I am going to vote, although for me ... it is all like a fog from Brussels," he said.
Britain's "Super Thursday" poll, so-called because it includes elections for local councils and for a London mayor, was shaping into a protest vote against Prime Minister Tony Blair for his support of the US-led war in Iraq.
Blair is universally predicted to fare badly on Thursday and that will inevitably fuel speculation about his leadership.
Poor showing by Labour would
fuel doubts about Blair's future
But most analysts still see him winning a third general election, expected in 2005, despite public disquiet over Iraq and his closeness to US President George Bush.
In the Netherlands, the centre-right coalition government of Prime Minister Jan Peter Balkenende was in a close battle with the opposition Labour Party as domestic issues like the economy, jobs and spending cuts dominated.
The Netherlands was to release provisional results on Thursday night - the first country to do so - despite a row with the European Commission over making them public before the rest of the bloc has finished voting on Sunday. The commission has threatened legal action.
EU parliament vote results are due from late on Sunday.
Like Blair, Italian Prime Minister Silvio Berlusconi was expected to pay for his support of war in Iraq.
Among incumbents, only Spain's recently elected Socialist prime minister, Jose Luis Rodriguez Zapatero, was likely to win a show of support from voters delighted by his swift move to pull Spanish troops out of Iraq.
Anger at slow economic growth and high unemployment, plus hostility towards EU "capital" Brussels, were fuelling the regionwide anti-establishment feeling and helping a mixed bag of far-right, nationalist and eurosceptic parties.
In Britain, the opposition Conservatives' hopes of gaining from Blair's discomfort have been spiked by the rise of the hitherto fringe UK Independence Party.
Its policy of EU withdrawal has struck a chord among Britons and propelled it to a near 20% showing in some polls.