Nick Clegg saw Lord Rennard's apology to four women who accused him of sexual harassment weeks ago but it was not released as the former Liberal Democrat chief executive did not want to damage the party in the run-up to last week's elections, a friend of the peer has claimed.
Lord Carlile, a legal adviser to Lord Rennard, said the Deputy Prime Minister knew about his friend's apology weeks ago but at the insistence of the peer it was not released.
The former election strategist's mea culpa emerged last night and has instead heaped more pressure on Mr Clegg after a desperate week following disastrous local and European election results.
Lord Carlile told BBC Radio 4's The World At One: "Lord Rennard was absolutely very concerned personally not to do any possible damage to the party in the run-up to last week's local and European elections.
"So although this apology was seen for example by the party leader (Mr Clegg) weeks ago now it was held back until the elections were over."
Asked if Mr Clegg told Lord Rennard to hold the apology back, Lord Carlile replied: "No, no, no, absolutely not. Chris Rennard went absolutely out of his way to ensure and try and make it absolutely clear that nothing further should happen in this case until after the elections."
Lord Carlile also claimed Mr Clegg and party president Tim Farron put out "misleading" press releases calling for Lord Rennard to apologise for his actions without seeing the independent report into the peer's behaviour by Alistair Webster QC.
"On January 16 the party leader (Mr Clegg) and the party president (Tim Farron) issued press releases which when three months later Lord Rennard was shown the report were shown to be inaccurate and misleading.
"And I'm sure they were misled by party officials and I'm sure that Mr Clegg and Tim Farron, the party president, cannot have read the Webster report when they issued those misleading statements.
"They commented after I assume being misled as to what was in it.
"It's an accurate allegation, I don't know who to make it against as I don't know who briefed Mr Clegg."
Friends of Lord Rennard are now demanding he is reinstated to the party after complying with the recommendations of an independent inquiry, putting more pressure on the Mr Clegg, who has just seen off a supposed leadership challenge.
His most senior colleague, Vince Cable, has been forced to deny plotting to oust him - a change being openly demanded by some MPs and activists.
Lord Carlile also said Lib Dem members should be consulted on Mr Clegg's position as party leader.
He told the programme: "The Liberal Democrats have the internet addresses I suspect of at least 80% of their members so it wouldn't be difficult to consult.
"The old liberal tradition of consulting members could not be more sound than in this situation, so if I have anything to offer to this discussion it's 'stop listening to grandees sounding off, ask the members'."
Lord Rennard's expression of regret followed more than a year in which he responded to a series of complaints about his past behaviour by denying any wrongdoing.
After police dropped an investigation into the allegations, a probe carried out for the Lib Dems by Mr Webster concluded there was broadly credible evidence he had violated personal space.
But Mr Webster found no breach of party rules could be proved beyond reasonable doubt, and merely suggested Lord Rennard should say sorry to the four women - Susan Gaszczak, Alison Goldsworthy, Bridget Harris and Alison Smith.
When Lord Rennard refused to do that, he was suspended in January for bringing the Lib Dems into disrepute.
However, he threatened a legal battle to overturn the punishment, arguing that he had not been allowed to see the full report and risked opening himself to damages claims.
A statement supplied to the party by the peer's lawyers this week made clear he was apologising after being given access to a redacted version of Mr Webster's findings.
Three of the four women have appealed against the findings of Mr Webster's report, while Lord Rennard has appealed against the disciplinary process for bringing the party into disrepute by his failure to apologise.
Ms Harris told The World At One that Lord Rennard must be expelled from the Lib Dems.
She said: "I would just ask the question, who does Rennard speak for any more? He has been shown to have on many occasions acted completely and deeply inappropriately towards women and has taken advantage of his position as a very powerful member of the Lib Dems to do so.
"I think it's a fairly cut and dry case that the party as a whole should accept that they no longer have their favourite campaigner working with them and instead they have to ask him to leave and I think it's as simple as that."
In January, Mr Clegg issued a press release saying it was "clear" that Lord Rennard had behaved in a way that caused the women distress, while Mr Farron said it was "clear" he had not behaved as a party chief executive should.
Mr Clegg said: ''It's clear in the report that a number of women in the Liberal Democrats were subject to behaviour by someone who had a position of considerable authority which caused them real distress.
"That should not have happened and I, as leader of the Liberal Democrats, want to apologise to each and every one of those women again.''
He added: ''I am not content with the fact that a report concludes that - while of course we should respect the outcome of the report - that nonetheless the system is such that someone has been asked to apologise, distress has been caused, and yet there are no sanctions which can be applied.''
Meanwhile, Mr Farron said: "While this process has not found to a criminal standard of proof that Lord Rennard acted with indecent intent, it is clear that he did not behave in the way that a chief executive should behave. Lord Rennard must reflect on his actions and apologise to the women involved."
Mr Webster at the time said of his investigation that there was "broadly credible" evidence that Lord Rennard had "violated the personal space and autonomy" of the women.
He said: ''My view, judging the evidence as a whole, is that there is a less than 50% chance that a charge against Lord Rennard could be proved to the requisite standard.
''In my opinion, the evidence of behaviour which violated the personal space and autonomy of the complainants was broadly credible. However, it is my judgement , considering all of the evidence collected, that it is unlikely that it could be established beyond reasonable doubt that Lord Rennard had intended to act in an indecent or sexually inappropriate way. Without proof of such an intention, I do not consider that such a charge would be tenable.''
Speaking at a pro-UK event in Edinburgh, Lib Dem peer Lord David Steel said: "He's made his apology. I think he has tried to draw a line under what happened.
"I can make a very irreverent joke and say: trust the Liberal party to organise a sex scandal without any actual sex."
Fellow Lib Dem peer Baroness Shirley Williams said: "I'm inclined to agree with David, I think we should leave it for a bit and I think at some stage - what he did was frankly nothing compared to most of the BBC - I think eventually you have to let him come back again."