In this reduced era of four-parters instead of six, it can seem as if only two actors are in regular work: Stephen Graham and Olivia Colman. She appears in so many serious roles (last week, Accused) that I wonder if there's an entire audience which is unaware she also works often, and brilliantly, in comedy. This is a spoof melodrama about a mining dynasty.

Julia Davis stars alongside Olivia Colman and Sharon Horgan in a spoof of Latin American telenovelas from Peep Show writers Sam Bain and Jesse Armstrong. Sending up a genre that's already a send-up of itself is a tough ask, but they pull it off.

Comedy fans, prepare to be excited. This new pilot has impeccable pedigree, being written by Peep Show's Sam Bain and Jesse Armstrong and starring three of our funniest actresses: Olivia Colman (Rev.), Julia Davis (Nighty Night) and Sharon Horgan (Pulling). It's a soapy spoof melodrama - think Dallas done by French and Saunders - about a rich, dysfunctional mining dynasty. Cue face-slapping, bitching and deliberately clumsy exposition.

Olivia Colman: 'I like that she's not quite right'

Olivia Colman teams up with Julia Davis and Sharon Horgan for Bad Sugar, a wickedly funny new black comedy about a dysfunctional mining dynasty from the writers of Peep Show.

Olivia Colman interview

Her comic supporting roles endeared her to millions. But now Olivia Colman is showing her grittier side - and looking in every danger of becoming a leading lady.

Robert Webb: I worry people think I'm like Jeremy

Robert Webb tells Metro he's nothing like his Peep Show character Jeremy, why he hasn't watched co-star Olivia Colman in Tyrannosaur, what he has planned for David Mitchell's stag night and all about his new film The Wedding Video.

Sadly but inevitably, and inevitably brilliantly, the finis to Twenty Twelve. (Did you realise they couldn't even call the series 2012 because of "copyright" impositions by the gun-toting corporate carbohydrated school-sports greedfest?) The big question is whether Ian and secretary Sally did or didn't. Go away on holiday together.

The clue came in his earlier meandered musings to her about what he might do after these seven years of Olympic and divorce hell. "Nothing exotic. Just... rent somewhere in Umbria. Maybe some little village up a hillside, get up late, breakfast in a shaded courtyard... wander down to the bar in the old square in the evening, sit outside with a book and cool bottle of Pinot Grigio kind of thing." Not a bad premise, Ian, and the look on Olivia Colman's stoic, lovely face, yearning to give an unasked "yes", was paintable.

Of course they went. And that's all good then. But somehow, please, a spin-off.

There are fears that the fireworks at the Opening Ceremony will trigger ground-to-air missiles in London. Perhaps, wonders a member of the heroically dim Deliverance Committee, they could be incorporated into the display, even though the weapons "can't tell the difference between a Roman candle and a hijacked Airbus".

There are other problems: the Games' electric cars are under-powered, no one has thought to organise the national bell-ringing (called, with terrible, pin-brained inevitability, the Big Bong), and three of the team are fighting for the Director of Posterity job. But really, the last episode of this wonderfully silly comedy is all about the great unspoken love between Sally and Ian (Olivia Colman and Hugh Bonneville). Can they ever be together?

With a certain sporting event looming, it's the last ever episode of this marvellous mockumentary. As the Olympic Deliverance Team prepare to hand over to the Live Team, last-minute panics still need resolving. The fireworks planned by Danny Boyle for the opening ceremony will trigger the Army's ground-to-air missiles. Charging stations for the official Olympic electric cars work so slowly, the entire fleet will soon be stationary. And the special "Big Bong" peal of church bells, supposed to ring nationwide, has so far attracted only two entries. Cue BlackBerry-addicted "branding guru" Siobhan (Jessica Hynes) salvaging the crisis by roping in a celebrity. Will she land Sting or settle for Aled Jones?

Just to add tension, three colleagues have applied for the same post-Games job, with the shortlist about to be announced. Come handover day, Lord Coe isn't around to make his planned speech, having been "called away to argue with animal rights groups about a sheep", so Ian (Hugh Bonneville) steps in. Can he make it a rousing send-off? And will his excruciating but rather moving romantic tension with PA Sally (Olivia Colman) be resolved? Smart, superbly played and painfully close-to-the-bone.

In Twenty Twelve, Owen (Olivia Colman) hasn't actually declared her love for her Games-organising boss, but at least she's back as his PA to slice through "legacy", "diversity", "inclusivity" and all that rot, just as she would the lemon drizzle cake with which she keeps him sweet.