A Tory MP has said David Cameron apologised for the way he responded to a question she asked about the clout of the Lib Dems in the coalition.
At PM's Questions on Wednesday, Nadine Dorries urged Mr Cameron to show his deputy Nick Clegg "who's the boss".
Mr Cameron said he knew she was "very frustrated" but abandoned the rest of his reply amid laughter from MPs.
Ms Dorries claims Mr Cameron dropped his support for her abortion advice campaign after pressure from Mr Clegg.
In the event, Mr Cameron did not attend the debate on Ms Dorries' amendment to the Health and Social Care Bill, which followed prime minister's questions, which would have stopped abortion providers giving NHS-funded counselling to women.
It comes amid growing concern among backbench Conservative MPs that the Liberal Democrats are exerting too much influence over coalition policy across a range of issues.
In her question to Mr Cameron, Mrs Dorries said: "The Liberal Democrats make up 8.7% of this Parliament and yet they seem to be influencing our free school policy, health and many issues including immigration and abortion.
"Does the prime minister think it is about time he told the deputy prime minister who is the boss?"
The prime minister, struggling to get his reply out amid laughter from Labour MPs, replied: "I know that the honourable Lady is extremely frustrated about the... perhaps I should start all over again... I am going to give up on this one."
Ms Dorries told the BBC's Newsnight that the PM had contacted her personally after prime minister's questions to apologise for what took place.
"He was just caught unawares by what happened with the party opposite and the response," said the MP for Mid Bedfordshire.
"The prime minister had no idea I was going to ask him that question. You know if he did know I was going to ask him that question and he had responded like that, then one would think that something was machiavellian in his response. He had no idea I was going to be called."
Downing Street insisted that the prime minister had not intended any innuendo in his reply to Ms Dorries - despite what was read into it by guffawing Labour MPs - and he was referring to her frustration with the coalition government.
Simmering Conservative resentment about Lib Dem influence over policy came to the surface on Wednesday, with another Tory MP demanding a referendum on the UK's membership of the EU - something Mr Cameron has ruled out.
Many Conservatives also blame the Lib Dems for "watering down" the government's NHS reforms while prominent Lib Dems have made clear their opposition to getting rid of the 50% top rate of tax - a step many Tory MPs favour.
It also emerged on Wednesday that the first elections for police commissioners had been delayed by six months from May to November 2012 partly due to concerns about the impact of the earlier date on Lib Dem councillors facing re-election.
In a show of strength ahead of their party conference next month, about 90 Tory MPs are due to meet on Monday to discuss how to reformulate the UK's relationship with Europe.
MPs rejected Ms Dorries proposal on abortion counselling but the government promised to consult on improving the services offered to women seeking terminations.