Boris Johnson, a maverick with a history of diplomatic blunders, is a huge gamble by British Prime Minister Theresa May as her Foreign Secretary.

His catalogue of gaffes - of which the most spectacular was his zip-wire fiasco during the 2012 London Olympics - could fill a slapstick movie: "Carry On Boris".

Two weeks ago, his career at the top level of politics looked as if it might be over, when he dramatically pulled out of the Tory leadership race. But now zip-wire Boris has bounced back.

During his eight years as London mayor, he was accused of being too fond of globe-trotting. He claimed he was promoting the capital and its business opportunities.

His most controversial trip was a visit to British troops in Iraq last year, when he posed for photographs lying on the ground firing a Kalashnikov rifle, claiming he was aiming at Islamic State.

It was later revealed that Foreign Office officials were forced to pick up his personal bar bill, arrange his last-minute requests for sightseeing and block his attempts to visit the "front line".

Let's all remember Boris Johnson on his relationship-building trip to Iraq last year pic.twitter.com/mcBiPMSJXC

— Jack Stubbs (@jc_stubbs) July 13, 2016

In April this year, during the early stages of the EU referendum campaign, Mr Johnson was accused of "dog-whistle" racism by political opponents after he referred to President Barack Obama's "part-Kenyan" heritage.

The attack came after Mr Obama issued a controversial warning during a visit to London that the UK would be "at the back of the queue" in trade deals with the US if it left the EU.

In a newspaper column, he attacked the American leader for removing a bust of Winston Churchill from the White House in 2009. "Some said it was a snub to Britain," he wrote.

"Some said it was a symbol of the part-Kenyan president's ancestral dislike of the British empire - of which Churchill had been such a fervent defender."

Also in April, he won £1,000 in a competition for the most offensive poem on Turkish president Recep Tayyip Erdogan, run by the Spectator magazine, in which he described the leader having sex with a goat and calling him a "w*******".

Boris Johnson wrote this prize-winning poem on Turkey's Erdogan. Gonna be an akward meeting https://t.co/kw54VCpAFy pic.twitter.com/iRJ0b4z09q

— Shreeya Sinha (@ShreeyaSinha) July 13, 2016

In May, he accused the European Union of trying to unify under one "authority", as did Nazi leader Adolf Hitler.

"Napoleon, Hitler, various people tried this out, and it ends tragically," he said.

In a long history of diplomatic gaffes, he also flattened a child during a game of rugby in Tokyo and rugby tackled a German footballer, Maurizio Gaudina, during a charity football match.

Back in 1997, in comments he no doubt forgot when he campaigned for Brexit, he said of the EU: "Look, I'm rather pro-European, actually.

"I certainly want a European community where one can go off and scoff croissants, drink delicious coffee, learn foreign languages and generally make love to foreign women."

He caused huge offence when he called black people "piccaninnies" and people from Papua New Guinea "cannibals".

And he has described the religion of Islam as: "The most viciously sectarian of all religions in its heartlessness towards unbelievers."

Boris Johnson holds a press conference at Brexit HQ in Westminster last month | Photo: PA Images

Insulting Africa, Mr Johnson said: "They say [Tony Blair] is shortly off to the Congo.

"No doubt the AK47s will fall silent, and the pangas will stop their hacking of human flesh, and the tribal warriors will all break out in watermelon smiles to see the big white chief touch down in his big white British taxpayer-funded bird."

On China, which hosted the 2008 Olympic Games which he attended as London mayor-elect, he said: "Chinese cultural influence is virtually nil, and unlikely to increase."

And at the end of the Beijing games, at the celebration of London winning the Olympics in 2012, he said in a flamboyant speech: 'Ping-pong was invented on the dining tables of England in the 19th century, and it was called wiff-waff!

"And there, I think, you have the difference between us and the rest of the world.

"Other nations, the French, looked at a dining table and saw an opportunity to have dinner; we looked at it and saw an opportunity to play wiff-waff."

Of the former governor of California, Arnold Schwarzenegger, he said: "My speaking style was criticized by no less an authority than Arnold Schwarzenegger. It was a low moment, my friends, to have my rhetorical skills denounced by a monosyllabic Austrian cyborg."

But despite his earlier enthusiasm for the European Union, most of his undiplomatic outbursts have been directed at the EU.

"First they make us pay in our taxes for Greek olive groves, many of which probably don't exist," he once said.

"Then they say we can't dip our bread in olive oil in restaurants. We didn't join the Common Market - betraying the New Zealanders and their butter - in order to be told when, where and how we must eat the olive oil we have been forced to subsidise."

His new job as Foreign Secretary will make or break him.

If he curbs his gaffe-prone tendencies - which many Conservative MPs are convinced he is incapable of doing - he will emerge as a contender to be the next Conservative Party leader after Theresa May.

But if "Carry On Boris" carries on blundering and falls off the political zip wire, the new Prime Minister's gamble will have failed.

At the same time, however, she will have killed off his Tory leadership ambitions and his potential threat to her during her premiership.