Ed Balls will finally announce today that he is to join the race to become the next leader of the Labour Party.
The former schools secretary, who was one of Gordon Brown's closest advisers, has long been expected to compete for the position. His announcement follows the party's decision to throw out the idea of holding a snap leadership election this summer in favour of a longer, four-month contest.
Mr Balls will travel to the Midlands today to give a speech from Gedling, Nottinghamshire, a marginal constituency which Labour unexpectedly held at the election. Its MP, Vernon Coaker, is among those backing Mr Balls. His declaration takes the number of leadership candidates to three. David Miliband, the former foreign secretary, and his younger brother, Ed, had been the only others to officially launch their leadership bids.
There were concerns last night that a decision to give potential candidates just eight more days to throw their hat into the ring risked undermining the contest by blocking those struggling to raise the required 33 nominations from fellow MPs in time.
Labour activists are keen to have a wide choice of candidates to revitalise the party after its worst election result since 1983. Andy Burnham, the former health secretary, is another likely contender. However, like the three declared candidates, he had worked as a special adviser to New Labour ministers, leading many in the party to fear the four men are too similar to offer a real choice. Jon Cruddas, an influential left-wing backbencher, has already ruled himself out.
The successor to Mr Brown will be announced on 25 September, at the start of Labour's annual conference in Manchester, the party's ruling National Executive Committee (NEC) agreed yesterday. The decision is expected to help candidates such as Mr Balls and Ed Miliband overtake the frontrunner for the job, David Miliband.
Powerful voting blocs within the NEC, including the unions, were said to be pushing for a longer contest. Harriet Harman, Labour's acting leader, was also keen not to hold a snap election in July. Along with other senior party figures, she argued that the longer timetable will allow the party to regroup and have a longer debate about the future. In an attempt to boost participation, new members joining the party as late as 8 September will be given a vote. Hustings will take place during June and July, with members of the party balloted between 16 August and 22 September.
"It is going to be a very important opportunity for us to reflect on the result of the general election, to renew the Labour Party and to re-engage with the British people," she said. "We're asking people to join us and to help shape the progressive future of this country by joining the Labour Party so that they too can play their part in this great election campaign."
Yesterday, figures on the left of the party criticised the lack of time given for hopefuls to raise support. Last night, Mr Cruddas called the imminent deadline an "absolute nonsense" that would narrow the field. "Ed, Ed and David have been ministers since the day they were MPs," he said. "I've known some of them for 20 years but I don't know what they stand for. We should extend this and allow them to define what they are."
John McDonnell, who unsuccessfully attempted to run against Mr Brown the last time the party selected a new leader, said the curtailed timetable was an attempt to "fix" the election process. "It prevents rank and file party members having any say over the process," he said. "Labour MPs will have no real opportunity to consult their local parties and constituency parties will have no time to meet.
"Curtailing the nomination process so drastically in this way [discredits it] from the start."