Nick Clegg is expected to admit he was aware of general concerns over the behaviour of former Lib Dem chief executive, Lord Rennard.
Rennard has been accused of sexual impropriety by two women in a report that was aired on Channel 4 news on Thursday.
Clegg will claim that he was not aware of specific sexual misconduct claims, reports the BBC.
The deputy PM is said to be furious that some are accusing him of a cover-up.
The Mail On Sunday report one of the women who has made allegations wrote on Facebook back in 2009: "I just don't know how nick can know and not do anything.. :-( makes me very sad."
On sunday morning, business secretary Vince Cable denied that he or Clegg knew anything about the situation.
Speaking on the BBC's Andrew Marr show, Cable said: "The whole purpose of setting up a proper inquiry is to establish exactly who said what to whom, and whether these allegations were properly pursued at the time."
When asked if he was aware of complaints against the peer before the Channel 4 News report he replied: "Absolutely not."
He added: "Nick Clegg has also said he was not aware of these allegations until they appeared on TV last week. But they are serious, and we take them very seriously.
"It is obviously wrong if there are women there who have made complaints and felt they haven't been dealt with properly."
Lord Rennard - a key party strategist and adviser to a succession of Lib Dem leaders before standing down due to ill health in 2009 - has said he is "deeply shocked" by the allegations, which he "strongly disputes" and regards as a "total distortion" of his character.