Nick Clegg today put his authority as Liberal Democrat leader on the line demanding his party's peers remove the whip from Lord Rennard until he apologises to the women who claim that he sexually harassed them.
Liberal Democrat chief whip Lord Newby and the party's leader in the Upper House, Lord Wallace, are expected to withhold the whip from Lord Rennard if he turns up for this afternoon's sitting in the House of Lords.
That would almost be appealed by Lord Rennard and thus trigger a vote of the party's peers do decide whether or not to readmit him.
Many Lib Dem peers are sympathetic to the plight of the party's former chief executive and believe he has been unfairly treated by the leadership.
They point out that he has not been found guilty of any charges of sexual harassment by an internal party review and is effectively being asked to apologise for something he has never admitted.
It is far from clear that they will back Mr Clegg's demand for the whip to be withdrawn.
But Mr Clegg made clear that a vote to restore the whip to Lord Rennard would be a challenge his authority and warned "matters would not rest there".
"Clearly it would be in defiance of basic decency, it would be in defiance of what the independent formal processes have recommended, in defiance of me and in defiance of the president of the party," he said in a round of interviews this morning.
He added: "That is why I hope it will not happen this afternoon. Clearly if it were to happen, matters would not rest there."
A number of Lib Dem members have suggested that Lord Rennard's refusal to apologise brings the party into disrepute, which could trigger a new disciplinary process resulting in the whip being suspended.
Lord Rennard won the backing of Lib Dem Euro MP Chris Davies, who and attacked Mr Clegg's handling of the row.
Mr Davies told BBC Radio 4's Westminster Hour: "This isn't Jimmy Savile, it is touching someone's leg six years ago, at a meeting, through clothing.
"This is the equivalent of a few years ago, an Italian man pinching a woman's bottom. How much more must this man be made to suffer through the media condemnation that comes out day after day fed by the party leadership?"
Mr Davies added: "The whole thing has become like the Salem witch trials... A good man has been publicly destroyed through the media with the apparent support of Nick Clegg.
It is completely out of proportion, nonsense and outrageous."
Lib Dem peer Lord Carlile, who has been offering legal advice to Lord Rennard, warned during an interview on the Sky News yesterday that the row could escalate.
He said: "Here, we have a situation in which there has been found to be no case against Lord Rennard but he is being lined up against the wall by people who are trying to force him to apologise in a way no lawyer would advise and in which he should not apologise for all kinds of reasons."
He added that if the whip was removed then "the matter could unfortunately end up in the public law courts".
He added: "Nobody wants that to happen and I don't begin to understand why Nick Clegg has intervened after a process which has been concluded in Lord Rennard's favour"
But Mr Clegg told Daybreak there were no grounds for "legal sabre-rattling", because the demand for an apology had not been instituted by him, but was recommended by Mr Webster, who said it was a matter of "common manners".
Mr Webster said: "The suggestion that Lord Rennard might wish to apologise was not one I envisaged as being contentious.
"I viewed Lord Rennard, from the weight of the evidence submitted, as being someone who would wish to apologise to those whom he had made to feel uncomfortable, even if he had done so inadvertently. I would consider it to be common manners."
Asked whether his inability simply to impose his will on the party in the Rennard affair exposed flaws in the Liberal Democrats' internal processes, Mr Clegg said: "I admit that some people sometimes think that, because I'm the leader of a political party, I somehow should act as if I'm the leader of a sect. I'm not.
"Of course, leadership is partly about direct powers. Leadership is also a process of persuasion and setting out your views."
Former leader Lord Ashdown backed Mr Clegg and signalled his irritation at Lord Carlile's role.
"I fear he is advising Chris Rennard as a lawyer, but not as a friend," he wrote on Twitter.
Lib Dem peer Lord Macdonald, a former director of public prosecutions, told BBC Radio 4's Today programme it was "perfectly reasonable" to ask Lord Rennard to apologise.
"I don't believe you can cherry-pick. If you are going to accept the primary finding, that Lord Rennard cannot be shown according to the criminal standard of proof, beyond reasonable doubt, to have behaved inappropriately, I believe you also have to accept the secondary conclusion, which is that according to Mr Webster there was broadly credible evidence that he had behaved in a way that violated the personal space of those women.
"As Mr Webster put it, that he had caused distress and that he should apologise."