Donald Trump spent a National Prayer meeting plugging The Apprentice

Donald Trump just cannot let some things go – particularly when it comes to his business interests past and present.

So at the National Prayer Breakfast in Washington DC, Mr Trump decided to spend his time plugging The Apprentice – the show he just happens to be executive producer of.

Mr Trump asked the religious leaders gathered to say a prayer for Arnold Schwarzenegger, the man who has taken over host of The Apprentice and whose ratings the New York tycoon has often mocked.

“We had tremendous success with The Apprentice. When I ran for president I had to leave the show,” he said, explaining his decision to stand down as host of the reality television show.

“They hired a big, big movie star to take my place, and we know how that turned out. The ratings are right through the tubes. It’s been a total disaster…so maybe we should pray for Arnold - for his ratings.”

This is not the first time that Mr Trump has made fun of his replacement on the show, which he hosted for 14 seasons.

In January, he tweeted: “Wow, the ratings are in and Arnold Schwarzenegger got “swamped” (or destroyed) by comparison to the ratings machine.”

Schwarzenegger tweeted back: “There's nothing more important than the people's work, @realDonaldTrump. I wish you the best of luck and I hope you'll work for ALL of the American people as aggressively as you worked for your ratings.”

On Thursday, the star of movies such as Terminator, was quick to hit back.

“Hi Donald, I have a great idea - why don’t we swap jobs,” he said in a video message. “You take over TV because you’re such an expert on ratings, and I take over your job so that people can finally sleep comfortably.”

Though no one knows quite how genuine their beef is, the latest comments will do nothing to harm ratings of the show.