The six contenders for the British Labour Party's deputy leadership go head-to-head in a televised debate today that may prove vital in the race to succeed John Prescott.
Presenter Jeremy Paxman will grill the six hopefuls live in a special edition of BBC2's Newsnight, featuring questions submitted by the programme's viewers.
The rivals are taking part in a series of hustings events around the country, attended by thousands of Labour activists.
But tonight's broadcast represents the best opportunity for many of the millions of trade unionists and hundreds of thousands of party members who have a vote in next month's elections to assess their appeal.
While Labour's complicated electoral college system makes reliable polling difficult, none of the candidates is believed yet to have built up a significant lead in what is expected to be a close-fought contest.
A good performance tonight could provide one of the candidates with the opportunity to make the necessary breakthrough to be declared deputy leader at Labour's special conference in Manchester on June 24th.
The debate comes as differences among the candidates emerge over public housing allocation and new powers for police to question anyone without them being a suspect.
Northern Ireland Secretary Peter Hain warned the measures floated this weekend could become "the domestic equivalent of Guantanamo Bay" while party chairwoman Hazel Blears described them as "a flexible and sensible addition to the range of police powers".
Justice minister Harriet Harman decried the way in which the media were briefed on the proposals before MPs were told and called for an end to the "culture of spin".
Another candidate, backbencher Jon Cruddas, last night called for Labour to commit itself to a new "pro-equality agenda".
Latest bookmakers' odds make Hilary Benn favourite to win the race to become deputy leader, with William Hill offering 13/8 on the International Development Secretary over the weekend, against 15/8 for Mr Johnson, 9/2 Ms Blears, 7/1 Mr Cruddas, 8/1 Ms Harman and 14/1 Mr Hain.
Ordinary party members control a third of the vote in next month's election, with another third going to around 3 million union members and other affiliated bodies and the remainder to the party's MPs and MEPs.
The victor will become Labour deputy leader when Mr Prescott steps down on June 27th, but incoming Prime Minister Gordon Brown will not necessarily appoint him or her Deputy Prime Minister.