Two Conservative MPs already under investigation by the party over claims of antisemitism have put their names to a letter published by the Daily Telegraph announcing the formation of a new group aiming to “safeguard British values” from “cultural Marxist dogma”.

The phrase ‘cultural Marxism’, which has become more popular among alt-right and far-right activists in recent years, was used by the Nazis, who described “Kulturbolschewismus” when they sought to accuse Jewish intellectuals of orchestrating the spread of Communism, as well as sexual permissiveness.

It appeared in the manifesto of far-right terrorist Anders Brevik. It is not clear, however, the extent to which these origins are common knowledge.

The MPs under investigation, Sally-Ann Hart and Lee Anderson, were signatories of the November 9 letter, which announced the formation of the Common Sense Group, made up of 59 Tory MPs and Peers.

In the letter, the group wrote they were “tired of being patronised by elitist bourgeois liberals whenever issues such as immigration or law and order are raised.”

Ahead of her success in the Tory marginal seat of Hastings last December, Ms Hart sparked anger when it emerged she had shared a video with an image apparently implying that the billionaire George Soros, who is Jewish, controlled the EU. It also emerged she had ‘liked’ the Nazi slogan “Ein Reich” on Facebook.

Mr Anderson, who successfully stood for election as the MP for Ashfield, also faced an investigation by the party over his membership of  a Facebook group in which Soros conspiracy theories were promoted and which included supporters of the far-right activist Tommy Robinson.

The results of the investigation into the MPs’ conduct have yet to be published.

But sources close to both MPs suggest they were amongst a group of Conservatives who expressed surprise when learning of the meaning attributed by some on the far-right to the phrase "cultural Marxism."

The JC can reveal that the  All-Party Parliamentary Group Against Antisemitism, headed by the Tory MP Andrew Percy and his Labour colleague Catherine McKinnell, have issued a clarification on the use of the phrase.

A briefing paper prepared by the Antisemitism Policy Trust was sent to all Conservative MPs and peers on November 11, warning that using the term could result  in their words “inadvertently” acting as “dog-whistle for the far-right”.

Writing for the JC, Mr Percy, who is Jewish, said many of those who had used the term ‘Cultural Marxism’ had expressed surprise that it could be used by those wishing to making antisemitic arguments and that “several undertook not to use it again.”

Also among the signatories of the Telegraph letter that used the term were the MPs  Philip Davies, Karl McCarthy, Ben Bradley and Jonathan Gullis. Lord Lilley and Baroness Eaton were among the peers to give it their support.

Mr Percy told the JC that he recognised the phrase ‘cultural Marxism’ “will likely be unfamiliar to many of the great British public”.

But the MP for Brigg and Poole said the term - which has been used in academic circles for many years - “has also been misappropriated by extremists”.

He added: “Several colleagues, seeking to make valid and reasonable points about the limits of freedom of expression, have used the saying and their words might have inadvertently acted as a dog-whistle for the far-right.

“My colleagues may not have previously been aware what cultural Marxism was, but now they are. I wrote to all Conservative MPs some time ago with a briefing note produced by our secretariat, the Antisemitism Policy Trust, having previously already spoken to a number of them about use of the phrase.

“Most expressed surprise at its alternative meaning, and several undertook not to use it again. I undertook to confront colleagues because there was a problem.”

Mr Percy said he did not intend to “divert attention from our party and onto another, I have no time for whataboutery.

“A problem arose. I acted,” he writes. “I did so in good faith and will follow-up with any MP or peer that uses the phrase unwittingly, or deliberately, in the future.”

The APPG co-chair then addressed the issue of  Conservative MPs alleged to have engaged with antisemitism during the last election.

He writes: “Following the review processes for these cases, the co-chairman of our party, Amanda Milling MP contacted me to make it clear that, whether found innocent or not, those involved had been eager to learn more about antisemitism, and asked that I ensure this happened.

“Again, working with me and the Trust on a good faith basis, we have found there is indeed an appetite to learn from those involved and that lack of judgement or knowledge, rather than antisemitism, is to blame.

“This should be a private matter but I am making it public today to give confidence that when cases arise, we will not simply sit by.”

Last week Tory chair Ms Milling told the JC: “We do not tolerate racism, prejudice, or any discrimination at all.”