Britain's Got Talent bosses have gone into “panic mode” after failing to replace judge David Walliams.
The Little Britain star’s place on the panel remains empty just nine days before auditions begin at the London Palladium.
Graham Norton, 59, has turned down the role, and ITV bosses have reportedly failed to get would-be replacements Bruno Tonioli, 67, and Alan Carr, 46, to sign a contract.
BGT chief Simon Cowell, 63, is now considering bringing in various guest judges for the audition process, sources say.
This would give execs more time to sign someone for the live shows, which are expected to air in April.
An insider said: “Auditions start in just over a week and there is no confirmed fourth judge.
“It’s not quite a disaster yet but it would be fair to say we are entering panic mode behind the scenes.
“Simon is quietly confident a deal will be done in time.
“But there’s less confidence with production staff, who haven’t got a clue what’s going on.”
The X-Factor previously made use of guest judges such as Leona Lewis, 37, Geri Halliwell, 50, and Nicole Scherzinger, 44.
But the source added: “At this rate, hundreds of staff who work on the show may not find out what is happening until hours before filming starts.
"The uncertainty is making a lot of people very nervous.”
David, 51, had been a regular on the BGT judging panel since 2012.
During that time, he won Best TV Judge at the National Television Awards a record four times.
But the funnyman quit last year after audio was uncovered of him calling an elderly contestant a “c***”.
Judge Amanda Holden, 51, has backed her pal Alan Carr to fill the vacant seat.
But some producers and ITV execs are worried that having another comedian would be too similar to David.
And Amanda's fellow judge Alesha Dixon, 44, is reportedly backing Bruno, who she sat next to on the Strictly panel from 2009 to 2011.
Bruno is also a big hit with viewers – and signing him would see Simon get one over on Strictly.
The insider added: “BGT is used to running so smoothly because it has had the same four judges for the last 10 years.
“Most of the same production staff also return each year but there is currently a mix of concern and excitement that no one knows what’s going to happen.
“Simon is a big fan of both Alan and Bruno. He already knows they would be great additions to the show and have brilliant chemistry with the current judges. But BGT is a huge commitment to take on, time-wise, at such short notice.”
