Ex-Liberal Democrat chief executive Lord Rennard was prepared to offer a general apology to female activists for any upset he had caused before he was made aware of their allegations of sexual harassment which have caused a deep rift in the party.
In a comment made on Facebook the peer, who faces being barred from rejoining the party's group in the Lords unless he says sorry, said the offer was rebuffed.
In the message Lord Rennard indicated that he would not apologise now because it is not justified and further legal action was threatened, Channel 4 News reported.
Lord Rennard wrote: "I tried to make/consider any apology years ago, but was totally rebuffed by the complainants. One accepted then reneged! An appeal and further legal actions are threatened, so I could not apologise in any event even if justified (which it is not).
"It would damage the women and the party much more if I said any more."
A source close to the peer said: "He considered some years ago offering a general apology if he had ever caused offence in any way, but he didn't then know what the allegations were.
"Now he does know what the allegations are he denies them and therefore won't apologise."
Party leader Nick Clegg has issued an ultimatum, saying Lord Rennard should not have the Lib Dem whip reinstated until he says sorry.
One of the complainants, Alison Smith, said: "L et's be clear. Any apology from Rennard would need to be sincere and specific. Nothing worse than 'I'm sorry if...'"
Lord Rennard has strenuously denied the allegations against him from four female activists and disciplinary proceedings were dropped after an investigation by Alistair Webster QC concluded that there was a less than 50% chance of proving the case beyond reasonable doubt.
But Mr Webster recommended that Lord Rennard should apologise and consider changing his behaviour in future.
The women are understood to be appealing against the decision to end the disciplinary process.
Allies of Lord Rennard have been left furious by the way the situation has been handled and Mr Clegg has also faced criticism for not taking firmer action.
Ros Gordon, who chairs the Liberal Democrat Women (LDW) group, said: "LDW believe the entire process from the word go has been mishandled. As a result we have been left with an unsatisfactory position which has not been fair to anyone involved.
"We have been talking to senior members of the party about how LDW can contribute to resolving this distressing situation. Our involvement has been welcomed and we have been working behind the scenes to help in any way we can.
"We are speaking to the leader's office to arrange a meeting with Nick Clegg as soon as possible.
"LDW is aware that the women who made the allegations against Lord Rennard have raised an appeal. We call for the party to consider this urgently and give an opportunity for all sides to have their say through a formal disciplinary process.
"We will stand by our request for Lord Rennard to do the right thing and apologise to the women to whom he has caused distress whether intended or not. If he does not apologise we support the removal of the Lib Dem whip and we will be writing to the Lords to request it."
Leading lawyer and Lib Dem peer Lord Carlile, who has been acting as an adviser to Lord Rennard, said the party's handling of the situation "makes the North Korean legal system look benign".
But Mr Clegg received the support of influential former leader Lord Ashdown, who said on Twitter: "Chris Rennard and the Whip; I agree with Nick."
A decision on Lord Rennard's future within the party could come on Monday, when Lib Dem sources said the whip was due to be restored to him.
A number of Lib Dem members have also suggested that his refusal to apologise brings the party into disrepute - the charge that would have been levelled against him over the harassment allegations and which, if upheld, could lead to him being thrown out of the party.
If those complaints are taken up a new disciplinary process would begin, which would lead to the whip being suspended.
If not, Lord Rennard's fate could be decided by a vote of the Lib Dem group in the House of Lords.
A Lib Dem spokesman said: "Nick Clegg is of the view that, as long as Lord Rennard refuses the very reasonable request from Alistair Webster QC to apologise, it is inappropriate for him to rejoin the Liberal Democrat group in the House of Lords. Nick has communicated this to the Chief Whip and Leader of the House of Lords group."
More than 120 Lib Dem members said in a letter to the Daily Telegraph that Lord Rennard should be barred from any party body until he apologises.
The peer has indicated he will return to an elected position on the party's Federal Policy Committee now that the disciplinary process has ended.
The party activists wrote: " We believe that until he apologises and acknowledges the distress that his actions have caused, regardless of intent, he should never have had the Liberal Democrat whip restored and should be barred from any party body or involvement in any party activity that might facilitate a repeat of this situation.
"No apology; no whip."
The Daily Telegraph reported that the members of the Federal Policy Committee had written to its chairman, MP Duncan Hames, demanding that Lord Rennard apologises before being allowed back onto it.
The leaked letter made clear it would be "utterly untenable" for the Lib Dems to publish a policy paper on equality issues which had links to Lord Rennard.