The axe factor: Simon Cowell culls talent show judges as he searches for lost ratings

Simon Cowell confirmed his reputation as television's most ruthless power broker after dismissing the celebrity judges and host of the American version of The X Factor following the show's disappointing ratings performance.

Judge Nicole Scherzinger was shown the door along with the Welsh presenter Steve Jones. Paula Abdul had also been dispensed with, sources indicated, during Cowell's night of the long knives.

The cull was agreed at a London post-mortem into the Fox series held by Cowell and his most loyal "brains trust". The X Factor creator ruled that the show needed a "bigger celebrity" on the panel, according to The Hollywood Reporter, when it returns this year. By Monday evening, Jones and Scherzinger had been informed of their fate.

Yet the blame for the US X Factor's relative failure may lie with Cowell himself. He promised to deliver 20 million viewers to Fox but fell eight million short, hitting revenues at the Rupert Murdoch-controlled network. A rival NBC talent show The Voice, in which the judges aren't allowed to see the singing candidates, generated similar ratings to The X Factor but was deemed a success as expectations were set much lower.

Jones, who did not receive the news from Cowell in person, tweeted: "I won't be hosting next season's X Factor which is a shame but I can't complain as I've had a great time." Jones was said to have lacked the "heat" generated by the American Idol host Ryan Seacrest. Abdul, poached from Idol, was said to have become "irrelevant to the mix" after being blamed for the elimination of popular X Factor contestants. Scherzinger is tipped to become a judge on ITV's new search to find a lead for Jesus Christ Superstar with Lord Lloyd-Webber.

Created by Simon Fuller, Cowell's British talent show rival, American Idol has thrived without "Mr Nasty" and finished with 29 million viewers last May.

Cowell now wants to "take the show in a different direction", sources said, with L A Reid, the fourth judge, still apparently on board – but perhaps checking his inbox.

Nigel Lythgoe, the American Idol executive producer, gave Cowell a headache after announcing a potential coup – Idol has invited Barack Obama to sing a duet with Al Green, after impressing with a performance of "Let's Stay Together" in Harlem.