GMTV presenter Kate Garraway was fuming after Jonathan Ross made a joke about her relationship with professional dancer Anton Du Beke.

Jonathan’s jibe came after Kate revealed that she was planning to sue the Sunday Mirror for claiming that she had been cheating on husband Derek Draper with Anton, her former partner on Strictly Come Dancing.

Kate vehemently denied the allegations, saying they were “sad, hurtful and totally untrue”.

Jonathan commented on the story during the filming of Bruce Forsyth’s 80th birthday tribute.

On stage with Bruce, Jonathan joked: “What’s all this rubbish about Anton shagging Kate Garraway? He only gave her a hug. Mind you, he hugged my wife and now she’s pregnant!”

An onlooker said: “It was quite an uneasy moment. Kate didn’t look too happy.”

Bruce’s pals, including his Strictly co-host Tess Daly, attended the bash at the BBC TV Centre in West London on Tuesday.

Strictly dancers – including Kate and Anton – treated him to a series of show-stopping performances.