Both men confess they end up looking camp, prancing around on screen singing the likes of Gimme Gimme Gimme A Man After Midnight.

Pierce, 55 tells the ITV documentary The Mamma Mia Story: “I’m the last person you’d expect to see poncing around in platform shoes, tights and sequins.

“We had to do all these camp, dainty little moves and try to look butch. That was a challenge.”

Colin, 47, jokes: “Very few straight males of my generation would have put their hands up and claimed to have been an Abba fan in the Seventies.

“In fact if I had had a crystal ball in 1976, and seen this is the sort of thing I’d end up doing, I probably would have put a bullet through my head.”

There’s a remark the film’s publicists no doubt wish Firth hadn’t said.