One of them stood knee-deep in a toilet with Johnny Depp barking orders at him, the other made even Ricky Gervais turn away in embarrassment as he towelled his wobbly naked behind in front of millions.

It’s fair to say that, as career turning points go, Warwick Davis and Les Dennis will share the award for most humbling.

“Warwick still gets very nervous when we have to get dressed together,” admits Dennis, as his Spamalot co-star costumes up in their cosy shared dressing room.

There is an art to self-deprecation and it’s very much in vogue. Just look at the summer success of films like This Is The End and it’s clear that more celebrities than ever before are queuing up for a roasting.

Few, however, have pushed it as far as Davis and Dennis did when Ricky Gervais and Stephen Merchant hired them for their BBC ventures, Extras and Life’s Too Short.

“Self-deprecating in the absolute extreme,” is how Dennis puts it, especially of the scene which sees him inconsolable and stark naked in a panto dressing room.

Davis in turn recalls the horror of how his fictional self was made to do the Riverdance among other embarrassments by an over-zealous Johnny Depp.

“So much of the editing done on that show was just to keep Ricky’s laughter out of it – he forgets we’re filming. It was the most ridiculous thing but, in real life, if you’re trying to impress someone with the power of Johnny Depp, what could you do except go along with them?”

Revitalised

Poking fun at themselves so much – too much some would say – has given this unlikely duo a new lease of life. For Davis, Life’s Too Short opened up a whole host of comedic opportunities he’d never had before.

For Dennis, fictionally debating his rock bottom with the likes of Shaun Williamson (Barry from EastEnders) and Keith Chegwin has revitalised a career that had been up and down since his breakdown on Celebrity Big Brother.

Now, this change of fortunes has seen them working together once again in Spamalot, Eric Idle’s delirious musical spoof of Monty Python and the Holy Grail

“Somebody tweeted me the other day saying it’s just genius casting,” says Dennis, who plays King Arthur alongside Davis as his trusty companion Patsy. “We’d already worked together on Life’s Too Short, so when we come on stage, the audience just fall for it.”

Described as the “straight guy” of the piece, the show sees Dennis’ Arthur setting off in search of the Holy Grail on a fake horse as Davis follows behind clapping coconuts to imitate the sound of hooves. Surrounding the duo is a seasoned cast playing some of Monty Python’s best loved characters, who appear along the way in the hilarious grail quest.

The pair evidently love performing together, and even more so on Spamalot. When I finally pin them down for an interview one evening, it is about an hour before curtain up, yet both are relaxed, in good humour and all too happy to talk about the merits of their new West End roles.

“I was at school in Liverpool when Monty Python came out,” says Dennis, who delayed a holiday and move from his Highgate home to take the part. “It was before the days of video, so if you didn’t watch it live, you weren’t cool. You had to know it line by line. That’s the great thing as well, how many shows are there where the audience know the words as well as you?”

Davis conversely admits that, as a child, Monty Python’s oddball humour passed him by. As he grew older though, the 43-year-old Star Wars and Harry Potter star learnt to love the troupe and is now thrilled he is being offered the sort of roles that were until recently unavailable.

“Comedy is something I’d wanted to do for years. I loved watching it and being funny, but no one wanted to do anything with me.

“It’s often the hardest genre and takes a lot more work than people think. There’s timing, nuance, knowing when to take a pause or make it a bit longer – I’m finding that out now.”

Dennis concurs: “I’ve found there’s a musicality to the humour of Spamalot. Usually you’ve got to wait for someone’s laugh to die down before moving on, but here you push through and it just builds.”

It has been a busy time for the 59-year-old entertainer – he recently finished as a runner-up on Celebrity Masterchef, emerging, as he acknowledges, with a lot more dignity than he did in his previous reality TV appearance.

“In Big Brother, you sit on your backside doing nothing all day and it does drive you a bit mad. With Masterchef, though, I learnt so much and had a great time. From humble beginnings to preparing a three-course meal – it was stressful but so exhilarating.”

Commitment

Davis may not have had to cope with the irrepressible Gregg Wallace, but faced an equally challenging commitment last year when he was sent around the world with the king of Little England, Karl Pilkington, for An Idiot Abroad 3.

It was an experience he loved every minute of – even if his companion did not.

“I’d always said to Ricky, this guy doesn’t know how lucky he is to be travelling to all these amazing places. It’s hard for people to believe but that’s what Karl is really like – if he doesn’t like something, he’ll let you know.

“Of course, in all these places there was so much for him to dislike but that made it even better.

“It’s like when you watch it at home – the more miserable he looks, the more fun it was for me.”

The calendar dates for Davis are already crossed well into next year, with an upcoming tour of his Reduced Height Theatre Company set to hit the UK in early 2014.

Before that, Dennis is starring in a Christmas special of Midsomer Murders – yet another role you wouldn’t expect a former Family Fortunes overlord to try his hand at.

“That’s the problem,” the Liverpudlian says. “When you’ve been doing game shows for so long, you’re often pigeonholed. I’ve always done theatre, but people still come up to me and say ‘I didn’t know you could sing’.

“It’s nice to have a few aces up your sleeve though. It reminds me of when I did Hairspray a couple of years ago and one man came up to me afterwards.

“‘Les’ he said, ‘that was great – I didn’t know you were talented’.”