A live TV audience will question the three main party leaders in BBC One's Question Time this Thursday at 8.30pm.
Tony Blair has not been on Question Time for four years
Charles Kennedy, Michael Howard and Tony Blair will appear in turn each for nearly 30 minutes.
"It is a unique opportunity to see the three leaders interact with the same live audience" said Question Time Executive Editor Ric Bailey.
The SNP and Plaid Cymru leaders will appear in half hour programmes in Scotland and Wales the next day.
"It became clear months before the election that there would be no agreement on a US-style presidential debate between the leaders" said Bailey.
"We came up with the idea of this Question Time format and, after some negotiation, it was accepted."
It's a step forward from the last general election when each of the leaders appeared in their own separate edition of Question Time.
"The difference is that they'll actually face the same audience and we can carry the argument from one to another," said presenter David Dimbleby who will be in the chair as usual.
The programme will be broadcast live from London in front of a studio audience of around 160, selected to reflect the political balance of the electorate as a whole.
On arrival, audience members will be invited to submit a different question to each of the party leaders. The editorial team will then select which questions are used in the programme.
"As important as the candidates getting a fair hearing, I have to make sure the audience's questions get listened to and answered, not brushed aside," said Dimbleby.
"In the end it's up to the audience and they're the strength of Question Time.
"We can make sure the candidates get their fair share of aggresssive, stimulating or even hostile questions, and we can make sure the audience is a representative cross section of voters, but we can't decide what they're going to say.
"I suspect they could have quite an impact."
BBC One in Wales and Scotland will be carrying an additional programme in the Question Time format the following night with Plaid Cymru's Elfyn Llwyd and SNP leader Alex Salmond.
Question Time's election special with the party leaders is broadcast on Thursday 28 April from 2030 to 2200 BST.
The additional 30 minute Question Time programmes in Wales and Scotland are on Friday 29 April at 2130 BST.
All three programmes can be watched live and on demand from the BBC News website.