European politicians have reacted with horror to Boris Johnson’s appointment as Foreign Secretary.

The French foreign minister described the former London mayor as “a liar with his back to the wall”.

The German foreign minister meanwhile accused him of "monstrous" behaviour during the EU referendum, ion which he was the key cheerleader for Brexit

Others hit out at the Tory MPs record of insulting comments.

Labour MP Chuka Umunna, whose father was Nigerian, said that his first official meeting with President Obama would be interesting, suggesting that it begin "with the word 'sorry'".

Mr Johnson himself agreed that he owed apologies, not least to the Americans.

Earlier this year he appeared to cast doubt on President Obama’s motives when he described him as part-Kenyan and suggested that he harboured an "ancestral dislike" of Britain.

French foreign minister Jean-Marc Ayrault said: “During the campaign, you know he told a lot of lies to the British people and now it is him who has his back against the wall.”

Germany’s foreign minister, Frank-Walter Steinmeier, echoed much of the French criticism.

The European commission vice-president, Frans Timmermans, also accused Mr Johnson of borderline racism.

"Would it not have been enough to say that you disagree with the American president’s point of view?," he wrote in a blog posting.

"Why discredit not just his motives, but even his persona, with borderline racist remarks?”

Earlier this year Mr Johnson won £1,000 in a competition run by the Spectator magazine, for a limerick he composed describing the Turkish President having sex with a goat and calling him a rude name to rhyme with the Turkish capital, Ankara.

Last November local officials called off a visit to Palestine on safety grounds after the then-London mayor told an audience a trade boycott of Israeli goods was "completely crazy".

He also claimed that it was supported by "corduroy, jacketed, snaggletoothed, lefty academics in the UK".

At the time he was accused of a "misinformed and disrespectful" pro-Israel stance and there were warnings that he risked creating protests if he visited the West Bank.

Mr Johnson later claimed that his comments were "very much whipped up" on social media.

In 2008 Mr Johnson apologised for a 2002 Daily Telegraph column in which he described the Queen being greeted in Commonwealth countries by "flag-waving piccaninnies" - a derogatory term for black children.

The same column mentioned then Prime Minister Tony Blair being meeting "tribal warriors who will all break out in watermelon smiles" on an upcoming visit to the Congo.

In a November 2007 column in the same paper he described Hillary Clinton, the Democratic candidate to replace Mr Obama, as having "a steely blue stare, like a sadistic nurse in a mental hospital".

A later face-to-face encounter with Mrs Clinton was described as "frosty".

In an unexpected move Mr Johnson was also attacked by the US pop star Cher.

She was asked on Twitter what she thought of Johnson's appointment.

She replied: "Think He's F****** Idiot who lied to British ppl & Didnt have the (emojis of various sports balls) 2 lead them once 'leave' vote won."