Lord Sugar has branded former friend Piers Morgan a "coward" after finding himself blocked by the Good Morning Britain host on Twitter.
The pair suffered a spectacular fallout last year during the early days of the coronavirus pandemic, with The Apprentice host Sugar criticising Morgan for a series of provocative interviews with government ministers.
Morgan responded by calling Sugar, who had questioned some of the new social distancing rules, a "disgrace" and declared that their friendship was over.
In recent weeks Sugar has blasted Morgan for taking a trip to Antigua at Christmas which, although legal, appeared to be at odds with his plea to GMB viewers to restrain their behaviour over the festive period.
Morgan has not addressed his trip directly on the breakfast show, while many of the major media outlets have chosen not to fully pursue the story.
Nevertheless, Sugar hopes to convince Morgan to have him on GMB, writing on Twitter: "People [who] say I'm obsessed with @piersmorgan don't get it. He slags off people unfairly. I keep him in line and shut him up.
"He can't take his own treatment. He blocked me. He's a coward frightened to engage with me on twitter.I challenge him like he does to UK gov to come on @gmb"
In another post, he added: "I am old enough to be @piersmorgan father. I watched my own kids mature over the past 25 to make me proud. I have watched him and he has recently turned out a terrible disappointment. I am not sure if he can see it and not sure if there is any way back. #cowardpiers"
Sugar has also criticised Morgan's GMB co-host Susanna Reid, branding her "a nodding puppet".