A Conservative MP has claimed “cultural Marxism” is “destroying our children’s souls” and causing self-harm, suicide and “epidemic levels of anxiety”.

Miriam Cates, the MP for Penistone and Stocksbridge in South Yorkshire, told a conference in Westminster on Monday that young people would not have children if they did not have “hope for the future”.

She said: “That hope is sadly diminishing in so many of our young people today, because liberal individualism has proven to be completely powerless to resist the cultural Marxism that is systematically destroying our children’s souls.

“When culture, schools and universities openly teach that our country is racist, our heroes are villains, humanity is killing the Earth, you are what you desire, diversity is theology, boundaries are tyranny and self-restraint is oppression, is it any wonder that mental health conditions, self-harm and suicide, and epidemic levels of anxiety and confusion characterise the emerging generation?”

She added: “We must end the indoctrination of our children with destructive and narcissistic ideologies, instead protecting childhood, training children in the timeless virtues and teaching them how to love our country.”

John Mann, the Government’s antisemitism tsar, criticised Ms Cates’s use of the term “cultural Marxism”, saying it has its origins in a “conspiracy theory with antisemitism at its core”.

He said: “The use of the term is rooted in Goebbels’ cultural Bolshevism and is a conspiracy theory with antisemitism at its core.

“Its overlap with antisemitism today is seriously problematic and is part of the language being used to target Jewish people in very dangerous ways.

“No UK politician should be comfortable in using it and needs to understand where it comes from and why that is problematic.”

But Yoram Hazony, the conference chairman and an orthodox Jewish theologian, said the term is “apt”.

He said: “I deplore this attempt to smear a friend of the Jews such as Miriam Cates with the utterly preposterous accusation of antisemitism.

“The term ‘cultural Marxism’ is an apt phrase to describe the cultural agenda promoted by many on the left today. The Edmund Burke Foundation offers no platform to antisemites. We are proud to number Miriam Cates among our speakers and friends.”

Ms Cates made her comments while giving one of the opening speeches at the National Conservatism Conference, in which she called for families to be encouraged to have more children.

The former biology teacher used her speech to argue that falling birth rates were “the one overarching threat to British conservatism and indeed the whole of Western society”.

The UK’s birth rate has fallen over the past decade from 1.9 children per woman in 2012 to 1.6 in 2021, although that was a slight rise compared with 2020.

A fertility rate of under 2.1 children per woman is considered to be below the “replacement rate” and means populations will shrink without immigration. According to the ONS, the UK last had a birth rate above 2 in 1973.

As well as economic barriers to having children – including expensive housing, mounting student debt and a lack of support for childbearing in the tax and benefits systems – she said society had ceased to value children and parenthood properly.

“You cannot be socially liberal and economically conservative. If you think that government and society should have nothing to say about the conditions that promote strong families, don’t be surprised if you end up with a high-tax, high-spend economy, with a nation of broken people dependent on the state.”

She also attacked efforts to encourage women back into work quickly after giving birth, saying it “undermined” motherhood, and said current childcare policies treated mothers as “GDP contributors” who should “outsource their child to the state”.

She added: “People do what others value and so, as conservatives, we must seek to restore the value of children in British society.

“For children are not an economic burden. They are not a threat to personal autonomy or a lifestyle choice. Children are a joy and a blessing, they are the symptom and the cause of a society that has hope.

“Our children are the reason that we seek to rebuild a nation whose future is prosperous, safe and free.”