The heir to the throne, who was speaking at a fundraising dinner for the World Jewish Relief charity in London on Monday night, also urged people of faith to "extend a helping hand" "across the boundaries" of their own religions to wherever aid is needed.

In his speech, the Prince of Wales paid tribute to the work of the charity as well as a number of Jewish refugees and survivors of the Holocaust he had met throughout his life, including champion weightlifter Ben Helfgott.

"To meet Ben, and others who, like him, have endured indescribable persecution, is to be reminded of the danger of forgetting the lessons of the past," he said.

"The work of World Jewish Relief enables us to rally together, to do what we can to support people practically, emotionally and spiritually – particularly at a time when the horrific lessons of the last War seem to be in increasing danger of being forgotten."

His comments add to those made in his recent Christmas message in which he warned that the rising populism has "deeply disturbing echoes of the dark days of the 1930s".

Prince Charles wrote his speech before President Trump's Muslim ban was announced on the weekend but many in the room took his comments to be aimed at the US President.

Another speaker at the event, the Chief Rabbi Ephraim Mirvis, lashed out at the new president's recent executive order temporarily slamming the door shut on refugees and banning travel by residents from seven Muslim majority countries.

"President Trump appears to have signed an executive order which seems to discriminate against individuals based totally on their religion or their nationality," he told guests.

"We as Jews perhaps more than any others know exactly what it is like to be the victims of such discrimination and it is totally unacceptable."

World Jewish Relief raises funds to assist Jews around the world, particularly those living in the former Soviet countries, but also for humanitarian disasters afflicting people of any religion, including those caught up in the Syrian refugee crisis.

Monday's event was attended by prominent members of the British Jewish and arts community and raised £1.3 million ($2.2 million).

The dinner was held at the same time as thousands of protesters gathered outside 10 Downing Street, protesting President Trump's executive order and his planned state visit to Britain later this year, when he will be received by the Queen and stay at either Buckingham or Windsor Palace.

More than 1.6 million people have signed a petition calling for the President's State visit to be canned because it would "cause embarrassment to the Queen," triggering a debate in the House of Commons scheduled for 20 February.

The former permanent secretary of the Foreign Office, Peter Ricketts, warned that the state visit had put the Queen in a "very difficult position," and the trip should be downgraded to an official visit.

In a Letter to the Editor of the influential Murdoch broadsheet The Times, Lord Ricketts said the convention of the government protecting the monarch from being drawn into political controversy had been "put under strain because of the ill-judged advice to the Queens to rush out an invitation to President Trump."

"It would have been far wiser to wait and see what sort of president he would turn out to be before advising the Queen to invite him." He said no President had been issued an invitation for a state visit in their first year.

Prime Minister Theresa May is staring down the public pressure and complaints from MPs insisting the visit will go ahead.

"I have issued that invitation for a state visit for President Trump to the United Kingdom and that invitation stands," Mrs May said.

President Donald Trump with Prime Minister Theresa May on Friday. Photo: Bloomberg

Mrs May announced the state visit during her joint press conference with President Trump during her visit to the White House on last Friday.

The British Prime Minister was the first world leader to meet the President since his inauguration on 20 January. Britain is eager to quickly sign a free trade deal with the United States once it leaves the European Union's single market, as a result of the Brexit referendum. President Trump, the son of a Scottish mother and well-known anglophile, has said Britain will be placed in the front of the queue for a trade deal.

Mrs May's visit was initially viewed as a success but the prime minister quickly faced fierce criticism for declining three times to criticise the President's "Muslim ban".

Mrs May later issued a statement saying the government did not agree with the policy of excluding refugees and citizens from seven Muslim majority countries including: Syria, Libya, Iraq, Yemen, Iran, Sudan and Somalia.  British media has since reported she was given advance warning of the ban, which was announced on Saturday, during her visit on Friday.

A secondary row has broken out over whether President Trump should address the parliament from the symbolically significant Westminister Hall, following in the footsteps of Nelson Mandela, Barack Obama, Bill Clinton, Ronald Reagan and Aung San Suu Kyi.

On Tuesday local time, 73 MPs, mostly from the Labour and Scottish National parties, signed a motion urging a ban on the President from addressing the parliament.

During debate in the Commons, the veteran Labour MP Dennis Skinner, who was born in 1932, likened Mr Trump to Hitler and Mussolini.

"Do the decent thing and ban the visit, this man is not fit to walk in the footsteps of Nelson Mandela," he told parliament.

Labour Leader Jeremy Corbyn has also released a letter he wrote to Mrs May urging her to cancel Mr Trump's visit.

But the prime minister is also facing opposition from her own MPs.

Tory MP Sarah Wollaston has described the US President as a "sickening piece of work," not fit to stand in Westminster Hall.

"On his forthcoming State visit I don't think Trump should be invited to address both Houses of Parliament from Westminster Hall," the former doctor wrote on Twitter.

"Westminster Hall has great significance & should be reserved for leaders who have made an outstanding positive difference in the world," she said.

"That doesn't include Mr Trump."

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