“Dear friends” for over twenty years, comedian/impressionist Jon Culshaw and legendary comedy writer/producer Bill Dare from BBC Radio 4’s Dead Ringers have come together for an afternoon of unscripted, spontaneous comedy and conversation.

It might have been dark and drizzly outside, but Dare seems to have forgotten what time of day it is, greeting the audience with “good evening” and thanking them for queuing in the rain for this sell-out show.

Culshaw claims not to be a stand-up comedian, so the format for the Great British Take Off is based like a Parkinson interview (who Culshaw can nail perfectly). Both sit in stylish chairs, with Culshaw dressed in a rust-coloured velvet evening jacket and there’s an air of familiarity and great friendship between them both.

Culshaw sometimes sits and at others leaps to his feet to deliver his material, and once or twice sings to a backing track. Dare is a good MC, keeping the show running to time and on track, although with the audience helping to choose which characters will appear and what direction the show will take, no two shows will ever be the same.

No politician, sports personality or celebrity is off limits. From Donald Trump to Tony Blair to Gordon Brown to Alan Bennett, there really isn’t anyone Culshaw can’t impersonate, and he segues between each character with great aplomb and a natural ease.

He shares his stories of some fascinating characters from his youth growing up in Lancashire, and although we aren’t familiar with any of them, he is adept, through his facial expressions and mannerisms, at creating a picture of  Stan, his Liverpudlian boss, when he washed cars at Park Motors in Ormskirk.

Culshaw reveals the secrets of mimicry, such as that often the key to nailing a character will come from a piece of music, as for example Tony Blair’s inflection nicely plays out to ‘The wheels on the bus go round and round”.

Together with Dare, he reveals some of the mayhem of life behind the scenes in television and on the celebrity circuit, when he has to meet the people he impersonates. Chris Eubank claims that Culshaw hasn’t got his lisp right since he has had his teeth fixed, which is now more of a whistle, and he almost commits treason in front of H.R.H. Prince Charles, when at the prompt of a royal aide, he is asked to introduce our future king in his own voice. It’s initially met with disdain, but Prince Charles gets the last laugh on this one.

There’s also a rather lovely story of how in the guise of Tom Baker’s version of The Doctor, he meets Elizabeth Sladen (who played the Doctor’s original companion) in Ealing shopping centre. The show finishes with a nod to the Mike Yarwood, the “father” of all impersonators.

Not so much an evening of comedy but more one of great storytelling, anecdotes and polished impersonations, The Great British Take Off is a show that continues to give and with Culshaw at the helm, adeptly kept on track by Dare, promises to serve up some different bites each time.