Labour MPs will be told to "lighten up" and help open up the contest to find Gordon Brown's successor next week as the three contenders struggling to secure support are handed one last chance to appeal directly to their Commons colleagues.
Andy Burnham, Diane Abbott and John McDonnell are all yet to secure the 33 nominations needed from fellow MPs to help them on to the ballot paper. So far, only Ed Balls, David Miliband and Ed Miliband have crossed the line, with the Miliband brothers continuing to mop up additional votes. It has led to concerns the contest will effectively be another coronation, with a white, male, Oxford-educated former special adviser sure to win.
Labour MPs have so far refused to heed calls from unions and left-wing pressure groups to help the outsiders gain enough backing. Many of the about 80 MPs yet to declare are from the new intake, making their nominations hard to predict.
Campaigners have been spamming the inboxes of Labour MPs with messages demanding that they lend their support to one or other of the left-wing underdogs, Mr McDonnell and Ms Abbott. "Whoever's doing it really ought to check their facts," said one disgruntled MP. "I've already nominated."
In a private hustings scheduled for Monday, Mr McDonnell will tell those yet to make their selection to "lighten up" and allow a broad contest. All six contenders will compete for the votes of party members at the meeting. Nominations close on Thursday.
"Coronations have not worked well for this party in the past and that is what we will have if no other candidates are nominated," Mr McDonnell said. "The message I will be presenting on Monday is that the party is big enough to allow a full ring of candidates from across the party. MPs should listen to the view of party members, who want a broad choice. I don't understand why that can't happen."
The Fabian Society has also written to the candidates who have already secured enough support to earn their place in the contest, asking them to persuade colleagues to back the three remaining hopefuls. However, they have received only non-committal replies.
In reality, many of the undecided MPs are unsympathetic to the idea of deliberately backing a candidate who was not their first choice in order to widen the contest, believing that if they cannot win support from just 33 MPs they should not be in the race to lead the party into the next election.
The plight of Mr McDonnell and Ms Abbott now seems almost hopeless, although Mr McDonnell still hopes to be in double figures by the time he addresses MPs on Monday. Currently, the pair have attracted support from just a dozen colleagues between them.
Mr Burnham, the former Health Secretary, is still hopeful of securing enough backers, but it will go right to the wire.
The three men nominated have begun to make small gestures at how they will go about distinguishing themselves from each other, and from the Blairite and Brownite factions which divided the party since Tony Blair won the leadership in 1992.
David Miliband, now with a clear lead among MPs, has been associated with the Blairite wing of the party. His supporters argue that is unfair, suggesting he is a social democrat who is more focused on improving the plight of the worst off.
He has already signalled differences with Mr Blair over Iraq, and made a significant speech hinting that New Labour had been too fearful of the private sector to reform it.
Mr Balls is likely to have a more difficult time ridding himself of the baggage he carries from his days as one of Mr Brown's closest advisers. While he is likely to earn several endorsements from union leaders, many in the party regard him as tainted by the failure of the former prime minister.
Ed Miliband remains popular with the party rank and file, having carved out a niche to the left of his brother. He now plans to build on a past Labour success, the minimum wage, by swinging behind a campaign for a "living wage". He has also taken the lead on equality, supporting Harriet Harman's determination to ensure that half of the future shadow Cabinet are women.
His more fervent supporters say the moves, along with his brave decision to run against his brother, who has long been thought of as Mr Brown's successor, show a decisiveness that is lacking in David.
With a leadership campaign now likely to run until the end of September, the three men are conscious of saying too much, too soon. The pace with which they distance themselves from their former mentors is likely to remain their most challenging balancing act.
The contenders and their campaigns
Took an early lead among MPs and signalled a move to the left with comments on Iraq and backing the "living wage" campaign. Is winning some support from party members for promising to ensure half his shadow Cabinet are women, but risks scaring off wider audience.
Having overseen ID cards and NHS reform, he is conscious of needing to curb a Blairite image. Has attempted to do this by attacking executive wage levels. Still yet to get 33 nominations, not helped by launch of his leadership bid website, criticised as amateurish.
Undeterred by his failure to win enough nominations to run against Gordon Brown last time round, he has again made the case for a left-wing candidate to be allowed on to the ballot paper. A seasoned campaigner who will fight on, but nominations have been hard to come by.
Announced her candidacy live on radio, claiming other MPs had lobbied her to run. However, yet to reach double figures in the nominations race and has run a campaign so low-key some believe she had no intention of earning them. Her bid for power looks like going no further.
The frontrunner with broad support, but "relaunched" his campaign after his original declaration was criticised as lacklustre. Has begun distancing himself from a Blairite image by suggesting New Labour failed to reform the private sector.
Rumours he would struggle to find support proved unfounded and his understated campaign launch has impressed some who harboured doubts about his political style. Has already faced a tough interview on his closeness to Gordon Brown, an issue which is likely to return.
Campaign verdictReuse content