Harry Hill on Professor Branestawm, success, failure and his secret new musical based on "a global TV franchise"

But he gave it up. He wanted to trying something else out.

“If I kept going it would have probably got less good," he says of his decision to quit in 2012 after eleven years on the show. "You get to a point where you have done it enough and you want to do different stuff. I like doing things I fancy doing really.

“You have to keep the fun in it and not get put off by things that don’t work out for you and to do lots of different things. If you have all your eggs in one basket it's a problem. You have to test yourself.

“I could have stuck with TV Burp probably forever if I wanted to go completely mad. But the fun is developing new things really. Once you have worked out how to do it, you do it for a while and you have the fun of the success of it. But the real fun is trying new stuff really in pretty much anything you do.”

The "new stuff" he tried out was the 2014 show I Can't Sing: The X Factor Musical which he wrote with Steve Brown (AKA Glenn Ponder from Knowing Me, Knowing You with Alan Partridge) and starring ex-EastEnder Nigel Harman in the title role. It opened with a lavish premiere, attended by none other than Simon Cowell himself and the omens were good when the (pretty good) reviews came out. But it closed after just six weeks.

“I suppose I have a naïve arrogance in a way. I said: how about we write a musical about the X Factor? I have never written a musical before but I thought if Richard Stilgoe can do it I probably can do it. But actually when we met Simon Cowell and he said yes, me and Steve came out of the meeting and thought ‘what the hell are we going to do now?’"

“It was great. We did our job. It’s the way it turned out ticket wise. I learned a lot. One thing I do know is I really enjoyed the process and working with Steve and [director] Sean [Foley].

“People thought it will run and run and I will get my tickets later. That was one reason. But it’s a tough business."

But he hasn’t been disheartened and is having another go at another musical.

“Me and Steve Brown writing a new one about a global TV franchise which I can’t really talk about.

Is it Game of Thrones?

“No…”

“A reality talent show…?”

"No."

He won’t say any more. (My guess is Downton Abbey, but it's just a guess).

“It's been officially sanctioned but only happened in the last few weeks. We have started working on it it and I think it will happen.”

Another bold foray our of his comfort zone was his decision to present a series of singing talent show Stars in their Eyes which ran for six episodes on ITV in January and February 2015.

The revival was soundly beaten by The Voice on BBC1 and did not go down well with fans who campaigned to bring back old host Matthew Kelly. Hill doesn’t think it will return to ITV (ironically The Voice is poised to take its January slot in 2017 on ITV after the commercial network scooped the singing show from the BBC); or at least if Stars in their Eyes does come back it will not be with him in the presenting role, he maintains. But he is still pleased he did it.

"I did Stars in their Eyes which wasn’t a huge success but it was very interesting for me to try something like that which took me out of my comfort zone and which was a challenge. Some people might say I didn’t deliver on it but you have to go for things and be prepared to fail.

“I can’t see it returning with me. It was sort of…not quite….I think it was good actually. It was actually a lot better than a lot of shows. Perhaps another series we would have got the hang of it. But life’s too short."

Does he think he didn’t take it seriously enough? There was nothing "straight" about his presenting (in contrast to Kelly) and there was a feeling in many quarters that he was taking the rise out of the whole thing.

“I don’t know…I think I do have to undermine things. That’s my shtick. Actually I wanted to take it further in fact. I always think if we managed to get all the singing out of it it might just have worked…"

He admits that one of his children – he has three daughters called Kitty, Winnie and Frederica – recently told him “you need to get back on TV...you’re not famous any more". He laughs. "They do keep me grounded," he says.

But they may have to eat their words today when the second helping of Professor Branestawm, Harry Hill in Professor Branestawm Returns, airs, following last year's Christmas special.

The second film will follow in the footsteps of last year’s seasonal show which saw Fast Show star Charlie Higson distill Norman Hunter's classic children's books into a 60-minute drama.

Higson is the writer once again and Hill will once again play the eccentric Professor with returns for Vicki Pepperdine as the highly-strung housekeeper Mrs Flittersnoop and Fast Show star Simon Day who made a memorable Colonel Dedshott of the Catapult Cavaliers.

Once again, the Christmas special brings to life the almost-blind Professor's madcap scientific experiments in a plot fashioned by Higson around Hunter's many short stories about his exploits.

His children will also be pleased that he is developing a spoof cookery show for ITV - in the guise of Harry - which is poised to air on ITV later this year if the pilot he shot gets a full series.

"It doesn't take much of a leap for me to get back to him, I just put the suit an glasses on and look in the mirror and think, hmmm,, where have you been...?," he laughs. It's another risky project but it's a challenge he is grasping with both hands.

"Men in particular are quite resistant to change but recently I have come to think that’s what life's all about really."

Harry Hill in Professor Branestawm Returns airs on Christmas Eve at 5.20pm