David Cameron and Ed Miliband will take part in the first of the general election television set pieces today as they face a grilling from veteran interviewer Jeremy Paxman.
The pair will also face questions from a studio audience in the joint Sky News/Channel 4 programme.
Despite being in the same TV studio, the Prime Minister and Labour leader will not go head to head, but will be interviewed individually.
Mr Miliband won a coin toss on Sunday to decide the running order, and opted to be interviewed second.
The Conservative leader will be the first in the hot seat for an interview with Mr Paxman lasting up to 18 minutes, after which the 100-strong studio audience - a third of whom are Tory supporters, a third Labour backers and the final third undecided - will question him for a further 18 minutes, with Sky's Kay Burley moderating.
Mr Miliband will then take questions from the studio audience before he too is interviewed by Mr Paxman.
The programme - Cameron & Miliband Live: The Battle for Number 10 - is the first of a series of television events agreed by the broadcasters and political parties following protracted negotiations.
The Prime Minister agreed to appear in a single seven-way debate on April 2, but shunned a direct confrontation with Mr Miliband.
Mr Cameron, Mr Miliband and Liberal Democrat leader Nick Clegg will also feature separately in a BBC Question Time special on April 30, just a week before the nation goes to the polls.
The only other true debate of the campaign will take place on ITV on April 16, and pit Mr Miliband against Ukip's Nigel Farage, Natalie Bennett of the Green Party, Nicola Sturgeon of the SNP, and Leanne Wood from Plaid Cymru.
The final line-up follows years of wrangling between parties and broadcasters over whether and how to repeat the debates from the 2010 election campaign - which saw Gordon Brown, Mr Cameron and Mr Clegg square up three times.
Mr Cameron rejected previous proposals on the basis they did not include the Greens and insisted the sessions should not take place during the short election campaign that starts on March 30.
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