David Cameron’s potty mouth revealed to the nation

In public his language is crafted, his words carefully chosen and his statements checked for inadvertent offence. In private, though, David Cameron is said not to be averse to the odd bit of “Anglo-Saxon vernacular”. Or, to put it another way, he can swear like a trooper.

Yesterday it emerged that on top of allegedly referring to the Government’s environmental commitments as “green crap”, he has also taken a colourful swipe at his Liberal Democrat deputy Nick Clegg.

Mr Cameron is said to have jokingly referred to Mr Clegg as an “idle f***er” – teasing him for enjoying a meal with his wife while he was drumming up trade on a trip to India and the Middle East.

A senior Conservative revealed that Mr Cameron had phoned a friend in the racing industry to get the low-down about racehorses owned by Sheikh Mohammed bin Zayed Al Nahyan, the Crown Prince of Abu Dhabi, ahead of an official visit to the United Arab Emirates last week.

The Prime Minister met the Sheikh last Saturday, with the aim of persuading him to buy Eurofighter Typhoon jets for the United Arab Emirates. But when Mr Cameron called his friend, the man revealed that he was dining close to Mr Clegg and his wife Miriam at a restaurant.

Mr Cameron apparently said: “Tell him he’s an idle f***er. I’m out here batting for Britain while he’s having a nice dinner.”

However, it appears that the man chose not to pass on Mr Cameron’s remarks to his deputy. “Nobody has approached Nick in a restaurant to pass on a message from the Prime Minister,” said Mr Clegg’s spokesman. “And I’ve heard that from the horse’s mouth.”

This week has been a vintage one for the Coalition’s use of blue language. On Thursday it was reported that Mr Cameron had instructed aides to “get rid of all this green crap”, referring to the levies that some members of his party believe are unnecessarily pushing up gas and electricity bills.

Although Downing Street insisted that it “did not recognise the phrase”, the sentiment behind it triggered anger among senior Liberal Democrats – who used it again to defend the Government’s green policies.

Danny Alexander, Chief Secretary to the Treasury, said: “Anyone who thinks we should get rid of that is full of crap,” while Mr Clegg said: “It isn’t all crap, of course.”

The emergence of Mr Cameron’s use of colourful language is no great surprise to his inner circle – or indeed journalists whom he has privately addressed in the past as “bastards” and “f***ers”. But he has yet to be embarrassed by being caught on tape.

John Major when Prime Minister was famously recorded unawares referring to members of his cabinet as “bastards”. In the early days of broadcasting at the House of Commons, the then Speaker Bernard Weatherill was recorded retorting “f*** him” about one pushy MP.

More recently, the Tory MP Claire Perry, who has been the driving force behind the campaign against online pornography, had to apologise to the Speaker, John Bercow, after she wondered aloud whether she needed to give him a blow job in order to get to speak.