PORN star Stormy Daniels has compared Donald Trump’s manhood rather unfavourably in her new book to “the mushroom character in Mario Kart”.

Daniels, who alleges she slept with Mr Trump after a celebrity golf tournament in 2006, writes in her book Full Disclosure, that his genitals were “smaller than average,” but “not freakishly small.”

“He knows he has an unusual penis,” Daniels writes. “It has a huge mushroom head. Like a toadstool …

“I lay there, annoyed that I was getting f**ked by a guy with Yeti pubes and a d**k like the mushroom character in Mario Kart …

“It may have been the least impressive sex I’d ever had, but clearly, he didn’t share that opinion,” Daniels writes.

Daniels recounts her first impression of Mr Trump when they met.

“He had a red cap, a Trump crest as a placeholder for the MAGA slogan not one of us could see coming,” she writes.

Daniels says his bodyguard invited her to dinner, which ended up being an offer to visit Mr Trump in his penthouse.

Mr Trump has denied any affair with Daniels, although he admitted to personally reimbursing his personal lawyer, Michael Cohen, for the money Daniels received in the hush agreement.

Daniels says she kept quiet about the relationship for years, especially from her ex-husband.

The adult entertainer also claims that Mr Trump offered to help her cheat on The Apprentice.

“We’ll figure out a way to get you the challenges beforehand,” Daniels, whose real name is Stephanie Clifford, quotes the future president as saying. “‘And we can devise your technique,’” Mr Trump told her, she claims. “He was going to have me cheat, and it was 100 per cent his idea.”

Daniels added that whenever she saw Mr Trump on TV for years after their encounter, she’d say to herself: “I had sex with that … Eech.”

Daniels also reveals that in 2007 the pair was in a hotel room watching a Shark Week broadcast when he got a call from Hillary Clinton — who was then running against Barack Obama.

“He had a whole conversation about the race, repeatedly mentioning ‘our plan’ …,” she writes. “Even while he was on the phone with Hillary, his attention kept going back to the sharks.”

Daniels says she never thought he would become US president, even when he started winning.

“It will never happen, I would say,” Daniels writes. “He doesn’t even want to be president.

Mr Trump’s approval ratings are at an all-time low on the back of revealing books by Daniels and journalist Bob Woodward

Daniels also talks about growing up as Stephanie Clifford in Louisanna where she was sexually abused by a middle-aged man, beginning when she was nine years old.

Her lawyer, Michael Avenatti, said that people were focusing too much on the explicit details from Daniels’ book.