The final debate between the lead candidates will be held in the European Parliament this evening.
It is the highlight of an election campaign that has failed to excite voters.
The 90 minute debate will be the first one to involve all the main candidates and the first time Alexis Tsipras, the Greek chosen by the European Left, has agreed to attend. Previously the Greek Leftist has claimed to be too busy to debate with his fellow candidates.
Tsipras has also demanded that he speak only in Greek, despite having excellent English, the language other candidates will be mainly using.
He will be joined by Jean-Claude Juncker (EPP), Martin Schulz (S&D), Guy Verhofstadt (ALDE) and Ska Keller (GREEN).
This election is the first time leading candidates have been chosen to represent the pan-European political parties who have been campaigning across Europe, with the candidates saying the election winner will become head of the European Commission.
The main opposition to this has come from Herman Van Rompuy, who has called a meeting of the heads of state to select the new heads of the EU institutions. This year, the Council Presidency, Commission Presidency, European Parliament Presidency and head of the External Action Service will be replaced.
This is usually done behind closed doors and can take many weeks to come to a deal.
There have been a series of debates, but there has been little disagreement between them, as their visions for Europe seem familiar. As Martin Schulz, the centre-left candidate, said in the first debate "I don't know what differentiates us."
All the main candidates appear to be offering a slightly different set of policy approaches, none seem to be offering a grand vision for Europe - a continent stalled after deep austerity, the replacement of elected governments and a plummeting support for the EU.
So far, there has been no real discussion on the deeper issues facing Europe, or on how to overcome them.
Faced with a parliament where a third of MEPs could be from extreme or eurosceptic parties
A recent IPSOS Mori poll suggested that only 35% of voters would definitely vote, eight points below the 2009 figure. Cyprus, badly hit by the financial crisis is bracing itself for the lowest ever turnout for the European elections.
Ahead of the debate, the EPP is in a slight lead according to the pollsters.
The debate will be broadcast on TV in 15 EU member states, Ukraine and Canada, mainly on minor channels.
The debate begins at 21:00 Central European Time. More information