Prince Charles issues a rare and dire warning in the wake of Donald Trump's presidency.

Prince Charles has warned the lessons of World War II  and the Holocaust are in “increasing danger” of being forgotten.

The heir to the throne was speaking at a fundraiser for World Jewish Relief, a humanitarian agency, when he made the comments.

The Prince of Wales was recalling the story of the “indescribable persecution” Holocaust survivor and former Olympic weightlifting champion Ben Helfgott faced during World War II.

“The work of World Jewish Relief enables us to rally together to do what we can to support people practically, emotionally and spiritually,” he said.

“Particularly at a time when the horrific lessons of the last war seem to be in increasing danger of being forgotten," he added.

The Prince of Wales' reference to “the horrific lessons of the last war” were viewed by some in the audience as an attack on the Trump administration and the recent ban on Muslim immigration.

The Prince said Mr Helfgott’s experience reminded us not to forget history, saying: “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.”

“World Jewish Relief shows us how vital it is to learn lessons from the horrors of the past,” he added.

Here is full & powerful speech by our patron HRH The Prince of Wales on our work & why he supports it. https://t.co/shuFnL9u4R pic.twitter.com/WhiBo3fOry

— World Jewish Relief (@WJRelief) January 31, 2017

The fundraising event was held at the same time as thousands of protesters gathered outside 10 Downing Street, protesting President Trump's recent ban on Muslim immigration and his planned state visit to Britain later this year.

According to The Guardian, British Prime Minister Theresa May has remained firm on President Trump's state visit despite the protests.

The Prince became a patron for World Jewish Relief in 2015 and he has praised it's ongoing humanitarian efforts.

“It is about supporting local communities with what they feel they need and not about imposing solutions from outside," he said.