David Cameron has become embroiled in the row over claims a Conservative cabinet minister called a female writer a "slut".

The Prime Minister's spokesman said that he had not spoken to his newly appointed Defence Secretary Michael Fallon about the alleged incident.

But she added that Mr Cameron would never consider the use of such language appropriate.

Asked about the claims, she said: "Does the Prime Minister think the use of the word 'slut' is appropriate in any sense?

"No."

But she added that there was a "clearly a debate [about] ... exactly what was said" during the disputed conversation.

Mr Fallon has been accused of calling Bryony Gordon, a writer for The Daily Telegraph newspaper, a slut when he met her at a party in a London bar back in 2010.

But sources close to Mr Fallon deny that he used such a word.

Scottish-born Mr Fallon has already established a high profile in his new role.

Last week he was at the centre of a row over whether the Red Arrows RAF display team should have flown just the blue and white colours of the Scottish Saltire during their fly past at the Commonwealth Games opening ceremony in Glasgow.

Last year the Ukip MEP Godfrey Bloom quit the party after being censured for calling party activists "sluts".

Mr Fallon replaced Philip Hammond in last month's cabinet reshuffle. Mr Hammond was appointed the new Foreign Secretary after the former Conservative leader William Hague stood down from the post and announced his plans to leave Westminster at the next general election.

Ms Gordon wrote last week that a mystery Conservative minister asked her: "If you work at the Telegraph, do you know that slut who writes that column at the back of the magazine? What's her name? Bryony Gordon?"

She added that she had replied "Yes... I know her very well, because that slut is me."