Tower Block of Commons, Channel 4

What do our elected representatives in Westminster know? Apart from, clearly, how to fill in an expenses claim form. You can file all the usual complaints about Tower Block of Commons, a series in which MPs take up residence in sink estates. It uses the tired old Wife Swap format of sadistically throwing its subjects in at the deep end to watch them sink or swim. The editing is visibly manipulative.

How bald? I refer the honourable members to the recession-hit domes of Mark Oaten, or Iain Duncan Smith, both of them dumped in East London high rises and left to cope. The shadow children’s minister Tim Loughton was dispatched to somewhere similarly grim in Birmingham, while Austin Mitchell was sent north to Hull. In each case they were foisted on a host, invariably female, whose task was to show them the sights: the turds, the shards, the sharps.

The depth of the MPs’ ensuing shock was so profound you slightly wondered whether they weren’t, in the style of another documentary staple, faking it. Duncan Smith was advised that if he wore his suit he’d get egged. “What’s that?” he said, assuming this must be some form of tower-block argot. “Eggs,” his young hostess Charice elaborated. As in what you can’t make omelettes without breaking.

Charice had not heard of the former leader of the Conservative Party, or possibly of the Conservative Party itself

Needless to say it was the Labour member who seemed much the most loftily ignorant of working-class reality. You’d never have guessed, from Mitchell's blithe lack of awareness of how he came across, that one of Westminster’s self-styled mavericks was once a television presenter himself. In The Damned United a version of him stitches up Brian Clough in the studio. (Slightly pointless footnote: he was played in the film by the actor Mark Bazeley, who did the voiceover here.) Where the other MPs consented to stay with their hosts, kipping on an airbed or the sofa, Mitchell insisted on bringing his wife and having their own council flat. The production company got their revenge by sticking them in a shithole.

Thoughout, Mitchell wore the look of someone on a tolerably amusing jaunt. Unless it was all edited out, he was barely interested in his tour guide Selina, a former prostitute and recovering heroin addict. When she told him they were off to the methadone dispensary to get her daily fix, he actually chuckled. Much more of this, he said, and he’d leave an expert on drugs. Then again, maybe not. Mrs Mitchell empathetically explained to Selina that she understood all about addiction, as in her 30s she had a little penchant for painkillers herself. This was news to the budding narco-tsar she's married to.

How useful is Tower Block of Commons, other than for throwing further tomatoes at Members of Parliament? When Michael Portillo opted for a similar immersion in working-class reality, he had already left Parliament. Apart from Loughton, most of these self-selecting outsiders might as well have done too: a Labour dinosaur, a washed-up ex-leader and a failed leadership candidate who by May will have given up his seat. Oaten came across as personable but maybe not the sharpest tool in the box. Did he imagine that the camera wouldn’t watch him when he went off for a walk in his tower-block mufti of hoody and tracksuit bottoms? From a window the long lens caught him lying face-down on the grass, as if poleaxed by sniper fire. “Look at ‘im,” said his delightful hostess Cathy. “’E can’t take it. At the end of the week he’s gonna want a noose.”

As an image of political impotence, it sort of said it all. There is nothing any of these politicians can do. They certainly wouldn't coax a vote out of anyone they met. Charice had not heard of the former leader of the Conservative Party, or possibly of the Conservative Party itself. At least Oaten’s reputation went before him. “Ain’t you the one that got done by the rent boys?” enquired one passing youth. (This was helpfully subtitled, in case anyone missed it.) The only box anyone admitted ticking was marked BNP, whose hate-peddling apparatchiks probably enjoyed this apocalyptic slice of light entertainment.