Yiannopoulos, a British news editor at Breitbart who was permanently banned from Twitter in July 2016 for instigating abuse of the Ghostbusters actor Leslie Jones, says “you can get quite hung up on this child abuse thing”.

WARNING: The video in the following tweet is graphic in nature

He goes on to suggest that sex between “younger boys” and older men could be a “coming-of-age relationship … in which those older men help those younger boys discover who they are”.

He also details a sexual relationship he had with a Catholic priest when he was a teenager.

After the release of the video prompted outrage among conservatives on Twitter, Yiannopoulos used a Facebook post to deny supporting paedophilia and claimed the video had been “selectively edited”.

“I did say that there are relationships between younger men and older men that can help a young gay man escape from a lack of support or understanding at home. That’s perfectly true and every gay man knows it. But I was not talking about anything illegal and I was not referring to prepubescent boys.

“I was talking about my own relationship when I was 17 with a man who was 29. The age of consent in the UK is 16. If I choose to deal in an edgy way on an internet livestream with a crime I was the victim of that’s my prerogative. It’s no different to gallows humour from Aids sufferers.”

The American Conservative Union founded and hosts CPAC, which is being held Wednesday through Saturday outside Washington. In a tweet on Monday, ACU chairman Matt Schlapp said that “due to the revelation of an offensive video in the past 24 hours condoning paedophilia, the American Conservative Union has decided to rescind the invitation of Milo Yiannopoulos to speak.”

After the polarising Yiannopoulos was invited, his invitation sparked a backlash. The conservative Reagan Battalion blog tweeted the video clips Sunday in which Yiannopoulos discussed Jews, sexual consent, statutory rape, child abuse and homosexuality.

Later Monday, Simon & Schuster and its Threshold Editions imprint announced that “after careful consideration” they had pulled the book, for which pre-orders placed it high on Amazon.com’s best-seller lists.

The subject of intense controversy, Dangerous was originally scheduled to come out in March. But Yiannopoulos pushed back the release to June so he could write about the protests during his recent campus tour, including a cancelled appearance at the University of California, Berkeley.

At the time of his publisher’s decision Monday, Dangerous ranked No 83 on Amazon’s overall list and No 1 in the subcategory of “Censorship & Politics.”

More than 100 Simon & Schuster authors had objected to his book deal, which was announced last December, and Roxane Gay withdrew a planned book. Some bookstores had said they would not sell it, although the National Coalition Against Censorship and other free speech organisations had defended the publisher.

Threshold is a conservative imprint that has published books by President Donald Trump, who has defended Yiannopoulos, and former Vice-President Dick Cheney among others.

“We realise that Mr Yiannopoulos has responded on Facebook, but it is insufficient,” Schlapp said. “We urge him to immediately further address these disturbing comments.”

Schlapp said the invitation was initially extended knowing that free speech on college campuses is a “battlefield where we need brave, conservative standard-bearers.”

But he added: “There is no disagreement among our attendees on the evils of sexual abuse of children.”

Yiannopoulos writes for Breitbart News, considered by many a platform for the so-called “alt-right” movement, an offshoot of conservatism that mixes racism, white nationalism and populism.

Additional reporting by The Guardian