Yvette Cooper today dodged on whether Diane Abbott and other Labour MPs had been offered peerages to make way for Keir Starmer's allies.
The shadow home secretary stopped short of completely denying the claim, merely saying she did not 'know anything about that'.
Ms Cooper argued that the system included independent vetting of House of Lords appointments - although the watchdog would typically not block a former MP being elevated.
Meanwhile, one of Ms Abbott's closest friends suggested this morning that the veteran left-winger has still not decided whether to stand on July 4, despite Sir Keir humiliatingly conceding she will not be prevented from doing so.
Left-wing MPs have alleged that since Rishi Sunak called the snap election they have been offered a place in the Upper House if they stepped aside as a candidate.
There have been complaints that the leadership is attempting to fill Labour's safest seats with loyalists - including Josh Simons, head of the Starmerite think-tank Labour Together, and Luke Akehurst, a centrist member of the ruling NEC.
One outgoing MP told the Sunday Times: 'They offered me a seat in the House of Lords because some little boy wanted my seat.'
Yvette Cooper today dodged on whether Diane Abbott (pictured) and other Labour MPs had been offered peerages to make way for Keir Starmer 's allies
Sir Keir (pictured with deputy Angela Rayner yesterday) has heaped praise on Ms Abbott as he struggles to move on from the latest bout of factional infighting
Shadow home secretary Yvette Cooper stopped short of completely denying the claim about peerages, merely saying she did not 'know anything about that'. Baroness Chakrabarti - one of Ms Abbott's closest friends in politics - made clear there was no certainty she would stand
Another observed that when the ballot was triggered 'suddenly there was a flurry of people standing down' who had previously claimed they would be standing.
If Sir Keir wins the July 4 general election, he is expected to boost the number of Labour peers significantly.
The Labour leader has been accused of purging Left-wingers with Ms Abbott at the centre of the row. The 70-year-old, the first-ever black woman elected to Parliament, said she had been stopped from being a candidate after a long-running standards probe.
After days of speculation, Sir Keir confirmed on Friday that she is 'free' to stand as a Labour candidate in Hackney North and Stoke Newington on July 4.
Asked in interviews today about the claims that peerages were offered, Ms Cooper told Sky News: 'That's not the way the system works.'
She said: 'There's a whole process with the independent committee that will vet nominations, there have to be processes in terms of the numbers of nominations, designated by the Prime Minister and so on.
'So, no party can do that or make those sorts of commitments.'
Asked if Sir Keir had promised anyone a seat in the Lords, Ms Cooper said: 'That's not the way the system works.
'The thing that we do know is we've seen a series of quite shocking Conservative resignation honours list from Boris Johnson to Liz Truss, and Keir has already said that he would change the way that he approaches all of those things.
'Indeed, he's said that he wouldn't have a resignation honours list as well because it's been so distorted by the way that the Conservatives have done that.'
Pressed again on the BBC later she said: 'Not that I know of. I don't think that's the way the system works.'
She added: 'I don't know anything about that.'
Sir Keir heaped praise on Ms Abbott in an interview with The Observer as he struggles to move on from the latest bout of factional infighting.
'Although I disagree with some of what she says, in terms of the battles she has been through and the terrible insults she has had to rise above, I have actually got more respect for Diane than she probably realises,' he said.
Labour sources have said Ms Abbott is free to be the Labour candidate in her long-held constituency, with the NEC expected to endorse her candidacy.
In response to the news, Ms Abbott said her local party selected her as their candidate in 2022.
'But I will not be the official candidate until I am endorsed by the Labour National Executive at its meeting on Tuesday. So I am not saying anything until then,' she said.
Appearing on the BBC's Sunday with Laura Kuenssberg programme this morning, Baroness Chakrabarti - one of Ms Abbott's closest friends in politics - made clear there was no certainty she would stand.
'I hope she will take some time to consider what she wants to do. That's literally what I suggested to her as her friend,' she said.
Speaking at the launch of the Conservative Party campaign bus on Saturday, Mr Sunak hit out at Labour for its back-and-forth on the subject.
The Tory leader said: 'Just see what's happened over this Diane Abbott situation. And it confirms what we know about him: it's that he doesn't stick by anything he says, just constantly changes his mind.
Starmer told The Observer: 'Although I disagree with some of what she says, in terms of the battles she has been through and the terrible insults she has had to rise above, I have actually got more respect for Diane than she probably realises'
'And it's clear that Angela Rayner is in charge of the Labour Party and not him.'
It comes as Mr Sunak's election campaign was dealt another hammer blow as a new poll showed Labour's lead is at its highest level since Liz Truss's premiership.
A survey carried out by Opinium showed Labour up four points to 45 per cent, with the Tories down two to 25 per cent, putting Labour on course for a landslide victory.
The poll was conducted between May 29 to May 31 - at a time of uncertainty in Labour's campaign, suggesting that Mr Sunak's shock announcements on mandatory national service and tax cuts for pensioners have not impressed voters.