The Duke of Sussex said he is publishing his memoirs because he doesn’t know “how staying silent is ever going to make things better”.

In a trailer for an ITV interview with Tom Bradby, Harry justified his upcoming book, Spare, in which he claimed his brother William physically attacked him.

An extract from the book, published in the Guardian newspaper, described a confrontation at his London home in 2019, where he claims the Prince of Wales grabbed Harry’s collar and knocked him to the floor, ripping his necklace and shattering a dog bowl under his back.

Harry further claimed William had called his American wife Meghan “difficult”, “rude” and “abrasive” – comments which the younger brother said parroted “the press narrative” about his wife.

The Guardian said it was able to obtain a copy of the book, due to be published on January 10, despite strong security measures around its release.

The ITV interview is due to be broadcast two days before publication and, in a trailer, Mr Bradby asks: “Wouldn’t your brother say to you, ‘Harry, how could you do this to me after everything? After everything we went through?’ Wouldn’t that be what he would say?”

Harry replied: “He would probably say all sorts of different things.”

Mr Bradby, a former royal correspondent and current presenter of ITV News at Ten, is a friend of the Sussexes and has previously interviewed them for a documentary about their 2019 Africa tour.

He told Harry: “Some people will say you’ve railed against invasions of your privacy all your life but the accusation will be here are you invading the privacy of your most nearest and dearest without permission, that will be the accusation.”

Harry answered: “That will be the accusation from people that don’t understand or don’t want to believe that my family have been briefing the press.”

Asked if he will attend his father’s coronation later this year, he said: “There’s a lot that can happen between now and then but the door is always open, the ball is in their court.

“There is a lot to be discussed and I really hope they are willing to sit down and talk about it.”

Harry said he still believes in the monarchy but asked when asked if he believes he will play a part in its future he said: “I don’t know.”

The show, called Harry: The Interview, will be broadcast on ITV1 and ITX at 9pm on January 8.