Charles Kennedy is to star in EastEnders this Christmas when he takes part in a seasonal special.
Mr Kennedy will play the Ghost of Christmas Future
The Lib Dem leader will play the Ghost of Christmas Future in a sketch for the BBC One soap to be shown on Christmas Eve.
He will take part in a one-off variety programme with the cast, based on Charles Dickens' A Christmas Carol.
Critics dubbed Mr Kennedy "chat show Charlie" after previous TV appearances but the party insists his latest star turn will not damage his credibility.
Lib Dem MP Sarah Teather said: "It is cracking that the EastEnders team thought that Charles was the kind of person that their viewers wanted to see on a Christmas special.
"There's 16m viewers of this programme - what politician would turn down that opportunity? I guess the others weren't asked.
"It's a bit of fun and it's Christmas, even Victor Meldrew gets a special outing at Christmas."
But Guardian newspaper columnist Simon Hoggart said he thought it was a bad move.
He suggested the Lib Dems could have as many as 100 seats after the next election if they played things right.
"I don't think clowning around on EastEnders is going to help.
"We know that Charles Kennedy is one of the lads, he's a good bloke. With an election coming up what he needs to do is establish his seriousness," he told BBC Radio 4's Today programme.