The Labour Party's website is likely to play a pivotal role in the battle to be its next leader, it has emerged.
Gordon Brown could be the only leadership contender
MPs' leadership nominations will be published on the site, although party sources denied reports the list will be updated hourly to boost interest.
Nevertheless, opponents of Gordon Brown reportedly plan to use it to show growing support for David Miliband, in an effort to persuade him to stand.
MPs can nominate a candidate even if they have not entered the race.
If the candidate gathers 45 nominations, or 12.5% of the parliamentary party, they will be entitled to take part in a leadership ballot.
They will have until noon on the day after nominations close to decide whether to enter the race or not.
Mr Blair is expected to announce the timetable for a leadership and deputy leadership contest within days of 3 May's elections in Scotland, Wales and English local authorities.
Once the starting gun has been fired, MPs will have three Westminster sitting days to canvas leadership and deputy leadership nominations.
There are six declared runners in the deputy leadership stakes.
As in the last leadership contest in 1994, candidates will attempt to convert pledges of support from colleagues into firm nominations.
But the process is likely to be even more highly charged this time, as candidates track their opponents' progress on the party's website.
Reports, in the Guardian newspaper, that the website will be updated with nominations on a "near hourly" basis have been denied by party sources, who said there would be no "running commentary".
It is more likely to be updated once a day, as MPs' nomination forms will have to be checked and verified before names are posted on the site.
"It is not going to be a free for all," a party source told the BBC News website.
And Gordon Brown, who is thought to have the backing of the majority of Labour's 353 MPs, could still end up being the only candidate with enough nominations to get on to the ballot.
Left wingers John McDonnell and Michael Meacher have both declared their intention to challenge him, but it is not certain they will be able to gather enough support from MPs.
Like other opponents of Mr Brown, they are pinning their hopes on a sudden, last minute shift in sentiment away from the chancellor.
Mr Meacher told the BBC News website: "If the tectonic plates begin to move a bit anything can happen. Elections can take on a dynamic of their own."
Opponents of Mr Brown reportedly plan a "write-in" campaign in support of David Miliband, using the party's website list of nominations to generate a sense of momentum behind the environment secretary.
Mr Miliband has said he has no plans to stand for the leadership and has thrown his weight behind Gordon Brown saying he is "an excellent prime minister in waiting".
But opponents of Mr Brown have been briefing newspapers about the potential strength of support for him among Labour MPs.
'Nothing to lose'
One unnamed Labour MP told The Daily Telegraph it was "very clear" at least 50 MPs would back Mr Miliband in a leadership contest.
The MP told the newspaper: "There are a hell of a lot of people out there who have had a collision with Brown over the years. For them it is a no-brainer. They have nothing to lose."
Mr Miliband's supporters are seeking to generate enough support, from MPs, the trade unions and party members, to persuade him it is worth risking future relations with Mr Brown by mounting a leadership bid.
But the environment secretary was warned against such a move by Labour elder statesman Lord Healey, who warned he would be "wiped out" by the chancellor.
In a GMTV interview to be broadcast on Sunday, the former chancellor warned Mr Miliband not to "take the risk" of throwing his hat into the ring, adding he believed former home secretary Charles Clarke was the only figure who had a "real chance" of beating Mr Brown.
Mr Miliband is the latest in a long line of potential leadership candidates touted by Blairite opponents of Mr Brown.
Previous hopes include Alan Johnson, who decided to bid for the deputy leadership instead, Alan Milburn and Charles Clarke, who has still not ruled out a challenge.
Home Secretary John Reid has also been touted as a possible contender and is the only senior Cabinet member not to have publicly declared his backing for Mr Brown as the next leader.