A leading Jewish group has criticised a Conservative former minister for using the term “cultural Marxism” in a speech, a reference to a conspiracy theory often associated with the far right and antisemitism.

The Board of Deputies of British Jews said Suella Braverman should clarify what she meant, and pledge to not use the phrase again.

The Labour MP Wes Streeting said Braverman should apologise for using an “ugly and reprehensible term with antisemitic connotations”. He added: “Members of parliament should know better and she should apologise immediately or the whip should be removed.”

Hope Not Hate, which monitors far-right groups, said it was “deeply disturbing” to see an MP use such language.

The Fareham MP, who resigned as a junior Brexit minister late last year over Theresa May’s Brexit plans, used the term in a part of her speech that condemned what she called an increasing culture of censorship.

Speaking at an event on Brexit organised by the Eurosceptic thinktank the Bruges Group, Braverman stood by her language after a member of the audience questioned it and noted it had been used in the self-styled manifesto of Norwegian far-right terrorist Anders Breivik.

Cultural Marxism centres around a conspiracy theory that Marxist scholars of the Frankfurt school in inter-war Germany devised a manipulative programme of progressive politics intended to undermine Western democracies.

Many of the academics of the critical theory movement were Jewish, and the idea of cultural Marxism is closely associated with antisemitic conspiracy theories.

In her speech Braverman said: “We are engaging in many battles right now. As Conservatives we are engaged in a battle against cultural Marxism, where banning things is becoming de rigueur; where freedom of speech is becoming a taboo; where our universities, quintessential institutions of liberalism, are being shrouded in censorship and a culture of no-platforming.”

After the speech, during a question and answer session, the MP was asked whether she stood by the term, given its far-right connections.

She said: “Yes, I do believe we are in a battle against a cultural Marxism, as I said.

“We have culture evolving from the far left which has allowed the snuffing out of freedom of speech, freedom of thought. No one can get offended any more, we are living in a culture where we are putting everyone in cotton wool, a risk-averse mentality is now taking over.

“And that instinct for freedom, for risk-taking, for making mistakes, for innovation, for creativity, is being killed. And it’s absolutely damaging for our spirit as British people, and our genius, whether it’s for innovation and science, or culture and civilisation; whether it’s for statecraft.”

She added: “I’m very aware of that ongoing creep of cultural Marxism which has come from Jeremy Corbyn.”

A spokesman for the Board of Deputies said: “Suella Braverman MP may not have been aware of it, but the term ‘cultural Marxist’ has a history as an antisemitic trope. We would ask for her to clarify the remarks and undertake not to use the phrase in future.”

Joe Mulhall, senior researcher at Hope Not Hate, said: “This is deeply disturbing and disappointing language to hear from a Conservative MP. In fact, it’s worrying that a mainstream politician would even have heard of such a phrase, which is usually championed by those on the extreme right.”

Cultural Marxism was, he said, “a conspiracy laden with antisemitic undertones” and had been cited both by Breivik and the man who shot dead 50 people at mosques in Christchurch, New Zealand earlier this month.

Mulhall said: “Given the term is championed by many figures inside the alt-right milieu, no politician in their right mind should be promoting such an obviously fake conspiracy theory. These are ill-judged, ill-chosen words.”

Braverman has been contacted for comment.