Robinson is known for her sarcasm

Robinson's usual black suit will be replaced by a pink leather jacket in the one-off show, to be screened on April Fool's Day.

The usually acid-tongued host will offer encouragement and praise to contestants - for part of the show, at least.

"We don't know how long she will be able to keep it up," said a BBC spokesman.

Special editions of the show have proved popular before.

Robinson hosted a drag queen special

A sports edition featured Olympic medal-winning rower Matthew Pinsent and Tony Blackburn appeared on a DJ special.

There have also been panto, Elvis, hairdresser and 'memorable men' specials.

"We tend to do a lot of themed shows because they work so well and are always popular with the viewers," said a BBC spokesman.

Robinson's ruthless approach to hosting the show - and her merciless despatching of contestants who fail to make the grade - have made headlines in both the UK and the US.

The US famously bought up the show in 2001 and decided to keep Robinson as its quizmaster but television network NBC dropped it from its prime-time slot last year because of falling ratings.