Sadiq Khan has called Donald Trump the “poster boy of the far right movement around the world” in the latest episode of their public dispute.

The London mayor claimed the US president’s behaviour was normalising and mainstreaming the abhorrent views of white supremacists and other extremists.

He made the comments in an interview on the American progressive politics podcast Pod Save America released on the day Mr Trump arrived in the UK for his state visit.

The war of words was sparked when Mr Khan described the US president over the weekend as “just one of the most egregious examples of a growing global threat” and compared the language he had used to that of the “fascists of the 20th century”.

Mr Trump hit back by mocking the height of the London mayor and calling him a “stone cold loser”.

President Trump in Britain for state visit: In pictures Show all 40 1 /40 President Trump in Britain for state visit: In pictures President Trump in Britain for state visit: In pictures President Trump, Prime Minister Theresa May and Jeremy Hunt, the foreign secretary, pose for a photo during dinner at Winfield House, the US ambassador's residence in London AFP/Getty President Trump in Britain for state visit: In pictures President Trump and Prime Minister Theresa May share a laugh outside of Downing Street Reuters President Trump in Britain for state visit: In pictures President Trump walks with the Queen while other guests follow as they arrive at a state banquet in Buckingham Palace AFP/Getty President Trump in Britain for state visit: In pictures The red carpet is rolled out in front of Downing Street prior to the arrival of President Trump AP President Trump in Britain for state visit: In pictures President Trump meets with prime minister Theresa May for a business roundtable meeting at St James' Palace in London AP President Trump in Britain for state visit: In pictures President Trump makes a speech at the state banquet in Buckingham Palace Getty President Trump in Britain for state visit: In pictures President Trump and the Queen share a toast at the state banquet in Buckingham Palace Reuters President Trump in Britain for state visit: In pictures Philip May and Melania Trump attend a garden party for families of Downing Street staff on the second day of President Trump's visit Getty President Trump in Britain for state visit: In pictures President Trump meets with the Queen at Buckingham Palace as he arrives on the first day of his three-day state visit PA President Trump in Britain for state visit: In pictures A mixed crowd of supporters and detractors waits outside Buckingham Palace ahead of the arrival of President Trump Reuters President Trump in Britain for state visit: In pictures President Trump and the Queen view an exhibition of items from the Royal Collection that are of historical significance to the US PA President Trump in Britain for state visit: In pictures President Trump inspects an honour guard during a welcome ceremony in the garden of Buckingham Palace AP President Trump in Britain for state visit: In pictures The police block a road leading to Westminster Abbey, where Donald Trump is visiting on the first day of his state visit PA President Trump in Britain for state visit: In pictures President Trump walks with Prince Charles in the gardens of Buckingham Palace AFP/Getty President Trump in Britain for state visit: In pictures The McDonalds restaurant on Whitehall near to Westminster Abbey provides an excuse as to why they are not serving milkshakes today, though many have speculated that it is due to the recent trend of pouring milkshakes over right wing political figures Tom Batchelor / The Independent President Trump in Britain for state visit: In pictures Protesters with anti-Trump signs stand on Whitehall near Downing Street Tom Batchelor / The Independent President Trump in Britain for state visit: In pictures President Trump and First Lady Melania are welcomed by the Queen, Prince Charles and Camilla at Buckingham Palace EPA President Trump in Britain for state visit: In pictures King's Troop Royal Horse Artillery perform a gun salute to honour President Trump's state visit and to mark the 66th anniversary of Queen Elizabeth's coronation at Green Park Getty President Trump in Britain for state visit: In pictures A protester stands on Whitehall near Downing Street holding a sign with an anti-Trump message Tom Batchelor / The Independent President Trump in Britain for state visit: In pictures A supporter welcomes the president's visit on Whitehall near Downing Street Tom Batchelor / The Independent President Trump in Britain for state visit: In pictures A miniature Trump balloon in the protest on Whitehall near Downing Street Tom Batchelor / The Independent President Trump in Britain for state visit: In pictures A protester wears a "No Trumps" card in his hat as he walks nearby to Buckingham Palace Getty President Trump in Britain for state visit: In pictures President Trump walks with Prince Charles and a Buckingham Palace guard as he is welcomed on the first day of his three-day state visit AFP/Getty President Trump in Britain for state visit: In pictures Dedicated pro-Trump and pro-Brexit campaigner Joseph Afrane awaits the president's arrival at Buckingham Palace Tom Batchelor / The Independent President Trump in Britain for state visit: In pictures Crowds watch as Marine One, the helicopter carrying President Trump, arrives at Buckingham Palace PA President Trump in Britain for state visit: In pictures President Trump and First Lady Melania depart from Air Force one at Stansted Airport Reuters President Trump in Britain for state visit: In pictures Supporters of the president - and detractors of London mayor Sadiq Khan - await his arrival at Buckingham Palace Tom Batchelor / The Independent President Trump in Britain for state visit: In pictures President Donald Trump salutes an honour guard as he and first lady Melania Trump arrive at Stansted Airport AP President Trump in Britain for state visit: In pictures President Trump and First Lady Melania arrive at Winfield House, the US ambassadors residence in London AP President Trump in Britain for state visit: In pictures An anti-Trump protester awaits the president's arrival at Buckingham Palace Tom Batchelor / The Independent President Trump in Britain for state visit: In pictures Dedicated pro-Trump and pro-Brexit campaigner Joseph Afrane awaits the president's arrival at Buckingham Palace Tom Batchelor / The Independent President Trump in Britain for state visit: In pictures A protester mowed this message into a field nearby to Stansted Airport Born Eco President Trump in Britain for state visit: In pictures An anti-Trump protester awaits the president's arrival at Buckingham Palace Tom Batchelor / The Independent President Trump in Britain for state visit: In pictures A marching band parades down the Mall in front of Buckingham Palace ahead of the arrival of President Trump Reuters President Trump in Britain for state visit: In pictures Supporters of the president await his arrival at Buckingham Palace Tom Batchelor / The Independent President Trump in Britain for state visit: In pictures President Trump shakes hands with Jeremy Hunt, the foreign secretary Sky News President Trump in Britain for state visit: In pictures A policeman stands on the Mall, one of the roads leading to Buckingham Palace that is closed for the president's visit Reuters President Trump in Britain for state visit: In pictures Air Force One lands carrying U.S. President Donald Trump and First Lady Melania Trump arriving for their state visit to Britain Reuters President Trump in Britain for state visit: In pictures An honour guard await Trump's departure from Air Force One at Stansted Airport Sky News President Trump in Britain for state visit: In pictures President Trump and First Lady Melania depart from Air Force one at Stansted Airport AP

Asked about his spat with the president, Mr Khan referred to Mr Trump’s ban on Muslims entering the US.

He said: “Donald Trump basically is the poster boy for the far right movement around the world.

“He and I first came into interaction when he decided he was going to ban Muslims from coming into the UK, apart from me because I’m the mayor of London.

“Banning Muslims from going to USA is a bad policy, it’s not the sort of America those of us who love America know.

“We have seen a number of policies which do cause concern to those of us in London, UK, Europe. The ripples of what is said by the president of the USA are felt all around the world.

“A number of things he has said and done is causing problems, people in France, Hungary, Italy, the UK ... who are having their views which are abhorrent normalised and mainstreamed because some of the things Donald Trump has done.”

Mr Khan said that progress in LGBT+ rights, gender equality and other policies was now in danger of “going backwards”.

“In the last 70 years we have not had a war in mainstream Europe so it does worry me that the right(-wing) part of politics is setting the agenda, but what worries me more is the fruits of this will be exploited by the far right, and these fruits are poisonous.”

He also suggested that Mr Trump was damaging the reputation of the US. He said: “Many of the things that are being said and done by Donald Trump cause huge offence and I’m afraid that the reputation of America isn’t as great as it has been in the past because of the president.”

The mayor also repeated his view that it was wrong to give the president a state banquet, adding: ”The red carpet is not an honour that should be bestowed on this president.”

Mr Khan claimed the prime minister’s decision to invite Mr Trump had “backfired” and “has led to a situation where Donald Trump feels he can say and do anything because others will be sycophants.”

“We see the USA as our best friends.” he added. “That means surely that we must have a relationship where we can call each other out.

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