Theresa May has been urged to ban Donald Trump from the United Kingdom following his call for all Muslims to be banned from the United States.
The Republican presidential candidate has triggered an outcry after he said there should be a "total and complete shutdown of Muslims entering the United States" in the wake of terror attacks including Paris and in California.
Sunder Katwala, the director of the British Future think-tank which focuses on immigration, said on Tuesday the home secretary should consider blocking any attempt by Trump to visit Britain in response.
"Donald Trump’s call for a blanket ban on Muslims visiting America represents a real low in electoral politics. It is hugely irresponsible for a prominent figure like Trump to fan the flames of prejudice in this way," he said in a statement.
"The UK Home Office has set out clear guidelines which have led to the exclusion of preachers of hate from the UK if their presence here would not be conducive to the public good.
"Theresa May has excluded extreme Islamists on these grounds, and also kept out those who have fanned extreme anti-Muslim prejudice, such as the bloggers Pamela Geller and Robert Spencer. Trump’s statements are more extreme than theirs."
He added: "Unless and until Trump were to retract these highly prejudiced comments, there is a good case for making clear that he would be refused entry to the UK by the home secretary."
In a statement posted on Twitter, Trump said: "Without looking at the various polling data, it is obvious to anybody the hatred is beyond comprehension. Where this hatred comes from and why we will have to determine.
"Until we are able to determine and understand this problem and the dangerous threat it poses, our country cannot be the victims of horrendous attacks by people that believe only in Jihad, and have no sense of reason or respect for human life. If I win the election for President, we are going to Make America Great Again."
Katwala, said Trump's proposals were "ludicrous and unconstitutional" as well as a "gift to Isis propaganda, playing into the idea of a 'clash of civilisations'".
"It is important that the UK government makes very clear that this extreme view is rejected and repudiated in the strongest possible terms," he said.
"It would ban well over a million British citizens from visiting the US simply because of their faith background, including our business secretary Sajid Javid and our Olympic hero Mo Farah, among countless others people in business, academia, politics, sports, science and civic society."
It is not the first anti-Muslim statement Trump has made in his quest to secure the Republican nomination for president. He has previously claimed to have watched footage of American Muslims cheering after the September 11 attacks on New York, despite no TV station being able to find any such film.
Yvette Cooper, Labour's former shadow home secretary and leadership candidate, condemned Trump's comment as "ignorant and islamophobic".