Last Night's Viewing: The Politician's Husband (BBC2) - Paula Milne's entertaining drama is too fast and flimsy to reflect real life

The first woman you see in The Politician's Husband is vacuuming the floor of the Chamber of the House. The second is pushing a cleaner's trolley and the fourth is polishing the floor of a Westminster lobby.

The third is the odd one out, although first glimpsed in a depressingly conventional position for a woman in a political drama, in bed alongside her more successful husband. As Paula Milne's new political drama begins, Aiden Hoynes, Business Minister, is staring at a nasty crack in the bedroom ceiling and contemplating a big step, the "principled" resignation that he hopes will trigger a leadership contest. And his partner, a junior education minister, is preparing to be the dutiful wife. But Freya is destined for something more than mere "plus one" status.

Because it doesn't work out as Aiden hoped. As his team frantically scan the blogs and the Twitter feeds, his support evaporates and then his closest political ally delivers a coup de grâce from Westminster Green. Aiden is out in the cold. The interesting question, of course, is where Freya's allegiances lie, though no one present seems aware that this is a question that can have no satisfactory answer.

Fortunately, the opening scenes of Milne's drama are delivered at a pace that doesn't give you a lot of time to think – the collapse of Aiden's plot crisply delivered and rounded out with enjoyable detail. "It physically hurts, Dad," says Aiden, licking his wounds at home, an agony of disappointment that David Tennant made all too believable.

The couple have a son with Asperger's, a character who seems likely to play a double role as psychological explanation for Aiden's drive and a prospective maternal dilemma for Freya in the future. And while the scene in which they make love and wrestle over who's going to end up on top is heavy-handed, it does raise the intriguing possibility that Freya has actually been aroused by her husband's failure. Even good marriages can have such disloyalties in them.

When you have time to think there are more problems, though. The biggest of them is Freya's baffling passivity. She is supposed to be a rising star too, after all, and while you can believe Aiden might have overlooked her abilities, it's hard to understand why Milne doesn't give her a more assertive voice in her own drama. Instead, she's repeatedly presented as a political ingénue.

Having taken a promotion (at Aiden's insistence), Freya agrees to talk to the friend who betrayed him. "I thought we were meeting in your office?" she says furiously, as she arrives at his table in a House of Commons dining room. In which case, why agree to a change of venue that she knows will expose her to Westminster gossip? Is she a politician or isn't she?

Even more problematically, when she's finally pinned down on Newsnight it's as if we're simply supposed to forget that she's already issued a categorical statement of support for the Prime Minister over the policy that led to her husband's resignation. So we're invited to hang over a cliff that couldn't realistically exist, unless Freya was to prepared to expose herself as a hopeless flip-flopper. I'll watch, and probably quite eagerly too, given the quality of the cast and the emotional intrigue. But it's entertainment, not life.

Snodgrass, David Quantick's drama for Playhouse Presents, imagined a world in which John Lennon had walked out of The Beatles before they made it big. The only zebra crossing he strides over in this universe is the one on the way to the job centre, his only fame that of a might-have-been. Ian Hart was excellent as Lennon and the script beautifully captured Lennon's aggressive wit. But the heart of the thing was that it wasn't really about Lennon at all. It was about that bit of us that aches to be a Lennon when we're 20 and still does 30 years on.

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