Political correspondent Simon Marks didn't hold back as he issued a dire warning to King Charles on LBC, telling host James O'Brien that going to the United States for a state visit is a "risky" move. US president Donald Trump said today: "I know one thing, Prince Harry is not speaking for the UK, that's for sure. I think I'm speaking for the UK more than Prince Harry," which left a sour taste for Marks.

Marks said on the show: "[It is] of course is a ludicrous position for any president of the United States to take when referring to any other government. But then we get absolute clarity about the eggshells upon which the King and the Queen will be walking next week when they are here in Washington DC. He goes off on the riff about the ballroom, but then manages to take himself immediately to hitting out at the prime minister."

Another clip showed Trump saying: "Yeah, I love the UK. I think they made a big mistake on energy. We should open up the North Sea in Aberdeen."

Marks continued: "So how all of this is going to be choreographed next week, you know, when the King and the Queen are with him, and when they are not with him and he has access to reporters, including now, propagandists, in that White House briefing room, who are going to ask questions about the president's view of the UK.

"But even while they're here there is a tremendous risk that it's going to be open season again."

O'Brien asked: "Do you think he can [hold his tongue]? You watch him more closely than most people do." Marks' answer was a resounding "no".

O'Brien said: "He's not capable of doing what you just described, is he?"

"No, he's not capable of being in a position where he stops transmitting. This is a man who is transmitting 24/7," Marks said.