A dispute has broken out over alleged remarks by Tory policy review chairman Oliver Letwin on NHS privatisation.
The Tories deny Oliver Letwin used the words "no limits"
Mr Letwin was quoted in the Sunday Times as saying there would be "no limits" on private sector involvement.
Tory aides insisted Mr Letwin had not made any such comment to the paper and a party spokesman said there was "no basis" for the story.
But Isabel Oakeshott, who conducted the interview, said that was "absolutely, categorically" what he told her.
The paper said that, in reply to a question over the extent of private sector involvement, Mr Letwin said: "No limits, no.
"Let the commissioning bodies decide where patients can best be cured.
"If people can provide services under the NHS which are good services - social enterprises, private bodies or NHS foundations - if they can satisfy the commissioners within the NHS that the best way is through them, then they should be part of the show."
The Conservatives released a transcript of the interview which they said showed Mr Letwin did not use the phrase "no limits".
A party spokesman said: "Nothing that Oliver Letwin told Isabel Oakeshott is at variance with anything that has been said in the last 10 months by senior Conservatives.
The row comes as the Conservatives begin their annual conference in Bournemouth.