Ronnie Corbett

Ronnie Corbett: I don't know why I keep crying so much

It's an emotional time for Ronnie Corbett: he's returning to TV after 17 years and mourning the sudden loss one of his oldest friends, David Frost.

Ronnie Corbett to present show about pets

Ronnie's Pedigree Pals, which will be screened later this summer, allows pet owners to show off their animals.

After works about Spike Milligan, Tony Hancock and Dad's Army, writer Roy Smiles once again plunders Britain's comedy heritage for this play about Ronnie Corbett (Aidan McArdle) and Ronnie Barker (Robert Daws).

Smiles uses the device of one of Corbett's monologues and parodies of their sketches to explore the differences in the two men and how they first met. The re-creation of the sketches has a novelty value for those who remember them, but often only serve to remind us how good the original Ronnies were. And having to explain gags that worked on screen ("you've thrown your drink over me") is plain uncomfortable.

An interesting curiosity, but the uneven structure and wayward impersonations ultimately make it rather disappointing.

Taking a lead from 2010's Frost On Satire, Sir David takes a look at another endangered comedy format, the sketch show. Charting the last 50 years of wanton skittery, Frost speaks to masters of shows past such as Stephen Fry, Ronnie Corbett and Michael Palin, taking in the highs and lows of the format. No preview tapes were available, so whether we'll be treated to the notoriously barbed "Timmy Williams Coffee Time" sketch from Moty Python's Flying Circus, a barely disguised pop at imperial-phase Frost himself, we have yet to find out.

JLS's Ortise Williams buys Ronnie Corbett's old mansion

Oritse has splashed out on pint-sized Ronnie Corbett's old Surrey mansion - worth a cool £1.7million.

TV commissioners take note. Impressions aren't funny. The actual act of sounding like someone else is an impressive skill, especially if you can do more than one, but by themselves, impressions are not in the remotest bit amusing. Jon Culshaw may do a canny Tom Baker, but the mere act of sounding like Tom Baker is about as humorous as getting stuck in a lift. With Jon Culshaw.

So it was refreshing to see Terry Mynott bringing something very different to the TV impressions table in his rather bleak new sitcom The Mimic.

Dour, slow and not the cheeriest of concepts, The Mimic doesn't scream hit. The tale of maintenance man Martin Hurdle, who muddles through life with only his uncanny ability as a mimic to perk himself up, isn't a gag-fest. It ekes out jokes and woos you in with pathos and the likeable Mynott.

It wasn't the most sure-footed debut, but purely for bravery and trying something different, I'm willing to come back next week. Mynott could knock out 27 minutes of Terry Wogan and Ronnie Corbett impressions, but he's tested new waters here and his exploration of the mundane, outsiders and the ordinary showed brief glimmers of potential.

And the fact that he didn't just wheel out a Tom Baker impression means that I'm willing to give those glimmers a chance.

Partial though I'm not to the word "quirky", Channel 4's new midweek sitcom, The Mimic, made a special plea for it, perhaps along with "gentle" and also, at times, "funny". Here was Martin Hurdle (Terry Mynott), a man with a dull job amusing himself by doing impressions. Wogan and Ronnie Corbett have become too standardised to impress but you had to laugh at his Al Pacino and his James Earl Jones quibbling with Morgan Freeman. The show didn't entirely depend on mimicry and there was strong support from Jo Hartley as his live-in friend Jean and Neil Maskell (arch psychopath from Utopia) turned up as a compellingly neurotic newsagent.

The first episode found an anxious Martin meeting up with an old flame's 18-year-old son for a burger followed by a DNA test. "If I'm not your dad, we can still be friends," he said. It was droll but unexpectedly touching. When it came back positive, I almost had to stop eating my biscuit.

The idea behind The Mimic, starring the remarkable Terry Mynott, is that it accepts the truism as truth. This is a comedy about a man who can pose convincingly as Ronnie Corbett stuck in a postbox but has no life to call his own.

Martin Hurdle - even his name sounds like a personality flaw - works in maintenance at a pharmaceutical company. There is no hope of promotion from whitewashing graffiti off walls, so he disappears into a multi-coloured vocal hinterland where he can be any number of camp television presenters or, in the sharpest sequence, James Earl Jones and Morgan Freeman engaging in a Socratic squabble over who has the better Afro-American larynx for narrating documentaries about penguins.

This ability has not brought Martin any more joy away from work. He lives with Jean (Jo Hartley), a female flatmate who is equally propping up the bar at midlife's last-chance saloon. For all the richness of Martin's interior life set against his humdrum routine, The Mimic could easily struggle to escape its binary parameters, but this first episode swiftly introduced a second outlandish scenario: Martin has discovered that he may have fathered a child 18 years earlier. It's all subject to a DNA test, but when they meet in a pub, the boy is soon crossing his fingers that they won't be related after all. This is a worry Martin articulates to himself through the conduit of Wedding Crashers. "If I didn't know who this guy was, and it turned out to be this guy," says Vince Vaughn, " I would be pretty disappointed." Or was it Owen Wilson?

It'll be worth finding out where The Mimic, already promisingly weird, goes from here. A lot rests on how series creator Matt Morgan marries two distinctly left-field scenarios - incurable impersonator discovers he's sired an adult. It certainly revinvents a branch of entertainment that has felt for a while like a busted flush.

For a sitcom, this is at the loose, gentle end of the spectrum. There aren't many out-and-out gags, it's filmed on location, there's no laughter track - if it were an hour long, you'd call it a comedy drama.

Our sort-of-hero is Martin (Terry Mynott), who has a dead-end job doing site maintenance for a drugs company (called, cheekily, CelPharm). When we meet Martin, he's in a traffic jam, amusing himself with a scabrous impression of Terry Wogan ("It's mornings like this, I wish I was back in Phuket bouncing a ladyboy on each knee...") and we soon gather that this is Martin's Walter Mitty-style escape.

He may be a man adrift, but his impression of Morgan Freeman arguing with James Earl Jones is uncanny (his Ronnie Corbett less so). What threatens to shake up Martin's world is learning he may have a son he has never met. That's if the DNA test pans out...

Norton foregoes the usual physical challenges beloved of Comic Relief for a more sedentary affair: attempting to set the Guinness world record for most questions asked on a TV chat show, which should see him broadcasting into the wee hours of Friday morning. We can only hope that Graham also dispenses with his usual tipple of wine with guests, otherwise this chatathon is going to get very messy.

So far guests announced as appearing on the sofa include Ronnie Corbett, RT's Sarah Millican, Martin Freeman, Elle Macpherson, James Nesbitt, Louis Smith, Heston Blumenthal, Warwick Davis, Russell Tovey and Jimmy Carr, though you wouldn't bet against an American superstar or two turning up, too. Music acts will include Example, Paloma Faith, Hurts and Laura Mvula.

Graham will be assisted by co-hosts Terry Wogan, Frank Skinner and Nick Grimshaw, and viewers can help, too, by submitting questions via Twitter and Facebook. And by donating money.