Gaffes we have known – and they didn't love

The perils of live microphones have caught out a Prime Minister before, famously capturing John Major calling eurosceptic members of his own Cabinet "bastards" in 1993.

Mr Brown's predecessor Tony Blair also suffered embarrassment when then United States president George W Bush summoned him at a G8 summit with the words "Yo Blair", lending serious ammunition to those who felt Britain was too close to America at that time.

Another former Republican president, Ronald Reagan, faced a humiliating climbdown in 1984 when he joked prior to his weekly radio address that a bomb attack on Cold War foes Russia was to begin in five minutes, unaware he was being recorded.

In 2005 Jacques Chirac, when president of France, managed to insult the British by remarking: "One cannot trust people whose cuisine is so bad," unaware reporters nearby could hear every word.

And former Tory leader Iain Duncan-Smith drew ridicule when he began extolling the virtues of Newcastle United whilst talking in a suburb of arch local rivals Sunderland.

It is not just politicians who have been caught out by live microphones.

Prince Charles did not think he was being recorded when during a photoshoot he was heard to remark of nearby journalists "bloody people."

However perhaps the best-remembered gaffe came during the 2001 campaign when the then deputy Prime Minister John Prescott responded to having an egg thrown at him by punching the offender in the face, prompting a brawl on the streets.