Young people not having babies is the biggest threat western civilisation faces, a Tory MP claimed - with "cultural Marxism" to blame.
Miriam Cates told a right-wing gathering in central London that getting Britain reproducing again is "fundamental to our survival" as she claimed the education system is "destroying children's souls".
Ms Cates, a rising star on the Tory right, said would-be parents would not have offspring if they did not have "hope for the future" - and said children must be taught to "love our country".
Her remarks have sparked condemnation from the Government's advisor on antisemitism.
No fault divorces and too many youngsters going to university are among the factors putting them off parenthood, Ms Cates told the National Conservatism Conference.
She said: "I've heard many people say that having children is a lifestyle choice, but having children is about as much of a lifestyle choice as eating. It's fundamental to our survival."
Ms Cates lashed out at schools and universities teaching pupils that Britain's history is "racist" and that mankind is "killing the earth" - saying these are reflected in birth rates.
Back in the 1960s, she said, British women would have an average of 2.6 children, but this has now plummeted below 1.6.
Ms Cates continued: "For the first time ever last year half of women reach their 30th birthday without having a child.
"Perhaps you think there's no problem, or only a minor problem, or a problem for the future - but there simply is no future if we don't reverse this trend."
And she told audience members that this is an even bigger threat to the western world than climate change and Russian aggression.
"None of our philosophical musings or proposals will amount to anything longlasting unless we address the overarching threat to British Conservatism and indeed the whole of western society," she stated.
"No it's not climate change, it's not Russia or China or Iran, it's not the neo-Marxist ideology that is seeping through our institutions, it's not inflation or taxation or poor productivity, no.
"There is one critical outcome that liberal individualism has completely failed to deliver, and that is babies.
"Across the nations of the developed world the birth rate is collapsing."
She added: "If you want to be a national conservative, you need a nation to conserve."
Ms Cates warned the UK is "completely unprepared for what's coming down the line".
She told the conference 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."
Following the speech Lord Mann, the government’s independent adviser of antisemitism, told Jewish News that it was “just not appropriate for a parliamentarian to be using a term such as this.”
Asked about the term "cultural Marxism", he said: “It is antisemitism.”
And Labour's Dame Margaret Hodge told the newspaper:”It shows what a long journey we still have to travel, when MPs such as this can make such thoughtless contributions which are indeed offensive to Jewish people.”
Among those set to appear at the three-day conference are Donald Trump-backed senator JD Vance, who has called for a ban on abortion and appeared to support the far-right Great Replacement theory.
This idea, popular among white supremacists, holds that white American voters are being deliberately replaced by people from different ethnic groups.
Other controversial figures appearing at the conference include historian David Starkey, who has repeatedly provoked a backlash with his comments about race.
Most recently he claimed Rishi Sunak is "not fully grounded" in British culture.
National Conservatism is a global movement which claims that traditional values are being "undermined and overthrown". Its principals include addressing a "marked decline" in marriage and birth rates, and has called for restrictions on immigration.
This is the first time a conference has been held in the UK, but speakers at previous international events have included Hungarian autocrat Viktor Orban, US rabble-rouser Ron DeSantis and far-right Italian PM Giorgia Meloni.
