A poignant Holocaust Memorial Day (HMD) commeration ceremony has heard how the level of ignorance about the Shoah creates a "vacuum" in which "denial and distortion" can thrive.

This year's event took place as research showed that, not only do one in 20 British adults believe the Holocaust did not happen, 64 per cent either don't know or hugely underestimate the number of Jews murdered.

As survivors, dignatories and politicians gathered at the Westminster venue on Sunday, Holocaust Memorial Day Trust chief executive Olivia Marks-Woldman told the JC: "We thought the number of Jews murdered was such an iconic number... We were really surprised and very depressed at how few people could remember [it].

"What worries us most about these figures is that you have a high number of respondents who cannot even say how many Jews were murdered, it's much more likely to make them very suseptible if they come across Holocaust denial or distortions.

"I'm very worried that people who know so little will be vulnerable to fake news."

HMDT chair Laura Marks told the ceremony it was taking place "at a time of public discomfort and divisions", with "views too often expressed angrily or without nuance".

But she said it was "comforting" there would be around 11,000 HMD events across the country, "bringing people together".  

Speaking of the "frightening lack of knowledge" among Britons about the Holocaust, she warned: "Such a level of ignorance provides a vacuum for outright Holocaust distortions."

She made a veiled reference to the presence of Jeremy Corbyn, who is accused of tolerating antisemitism within his party, when she said: "We were asked if it was appropriate to continue to welcome some representatives knowing that this may cause distress to Holocaust survivors and refugees...

"But we know through independent studies that people who attend Holocaust Memorial Day events learn more, empathise more deeply and go on to do more to build a better future."

The 80-minute event mixed speeches from dignatories and testimony from Shoah survivors, both on film and live on stage.

Communities Secretary James Brokenshire began by telling the audience to remember: "Those whose lives were cut short and whose loss provides a stark and powerful legacy to us all that demands we challenge hatred and prejudice wherever it exists."

He mentioned rising antisemitism and added: "I want to reassure our Jewish community that you an intrinsic part of what makes Britain great. The Government will always stand by you to challenge bigotry and intolerance."

Survivor Mindu Hornick spoke of her experience of being sent to Auschwitz when she was just 12. She said: "I remember asking myself - how could the world remain silent?"

Throughout proceedings, actors Penelope WIlton, Nina Sosanya, Sheila Hancock and Sanjeev Bhaskar read from works about the Holocaust and genocides that have happened since.

Chief Rabbi Ephraim Mirvis said Shoah survivors were "among the most extraordinary people within our society".

This year's HMD theme is "torn from home" and Rabbi Mirvis said it was "fascinating" so many survivors chose to leave the countries they had come from to set up new homes elsewhere.

"That's because they took with them the essence of the homes they had come from - their beliefs, their values - fond memories of the people they loved so dearly," he said. 

"Having gone through hell on earth, they emerged being absolutely dedicated to recreate their homes. This they have done magnificently... with the same values and the same beliefs.

"They have been absolutely determiend to teach the world about love, about unity, about tolerance and peace and they have been equally determined to confront antisemitism and all forms of racism and prejudice."

Six candles were lit to symbolise the six million Jews murdered. They were lit by five Shoah survivors, two Kindertransportees and three survivors of the Rwandan, Bosnian and Cambodian genocides.

Cantor Jonny Turgel - the grandson of the late survivor Gena Turgel, then sang El Male Rachamim.

At the close of the event, LGBT chamber choir The Fourth Choir performed Somewhere Over The Rainbow which, the audience was reminded, was written by two Jewish Americans as the Kindertransport was taking place.

Eleanor Wolfe, whose father came to Britain with the Kindertransport, sang the words, while, on screen, pictures and names of Holocaust survivors were displayed, together with the name of the place in Britain where they made their new home.