TV UK, 1 December

Ghost Squad (Channel 4, Tuesdays at 10pm) is an unusual and subtle British cop show, which is also very much of its time. It dramatises the work of a shadowy undercover police unit charged with gathering evidence against corrupt police officers. Officially the unit was disbanded several years ago, but in fact (for the purposes of the drama at least) it continues to operate secretly.

We are used to ‘Internal Affairs’ departments from US cop shows, in which they are usually known as ‘the Rat Squad’ but in fact are treated somewhat ambiguously. Honest cops are supposed to hate the Rat Squad on the grounds that cops should stick together and concentrate on catching criminals rather than ratting out their own, but there is always an element of performance in this. NYPD Blue’s gauche Detective Medavoy expresses this well, muttering about ‘cheese-eating rats’ whenever Internal Affairs appear in the station house, but without much conviction. In fact, most TV cops acknowledge that the Rat Squad serves a purpose, and often collaborate pragmatically with its agents.

By looking at its subject from the inside, Ghost Squad reverses this ambiguity. It is ordinary police who are assumed to be on the take, brutal, incompetent or downright wicked. In this week’s episode, things turned out to be more complicated. The target was an old-fashioned, boorish and drunken police sergeant in Leeds, who seemed to have bumped off a local troublemaker and subsequently seemed to undermine the investigation into an assault on a fellow officer. In fact, he turned out to be a decent man struggling to hold the line on an increasingly anarchic beat, and not guilty on both counts. He finally finished his career by taking off his belt and beating a teenage girl, but by then we had every sympathy with him.

There was something of Little Britain’s Vicky Pollard in the girl gang depicted in this episode, with their shell suits and attitude, but these girls were no joke. We first encountered them chasing some boys through their estate, and after some obscene banter – there’s no respect – they were soon brutally attacking an off-duty policeman, reducing him to an unconscious lump and finally peeing on him. As the sergeant told his colleague/undercover investigator, the ASBOs aren’t working. Having endorsed the hell-in-a-handcart portrayal of contemporary British cities familiar from the news media, Ghost Squad had little choice but to elicit sympathy for an old-fashioned clip-round-the-ear copper.

But just as American cops’ sympathy for the Rat Squad is always provisional, so Ghost Squad is never going to endorse fully the traditional police culture against which it is defined. The squad is personified by its boss Detective Chief Superintendent Carol McKay, played by Emma Fielding (who could recently be seen playing a New Labour apparatchik in Playing With Fire at the National Theatre, and does a nice line in New Political Woman), ruthlessly manipulating her puppet (so far) DC Amy Harris, played feistily by Elaine Cassidy. That the central characters are women is no accident: their job is to bring down the macho culture of the police from the inside.

Ghost Squad is thus an inescapably political drama, but well enough done to be alive to the contradictions of its politics. With last year’s Murder Prevention now being repeated on Channel 5, with its shadowy, politicised police squad tracking criminals before they strike, it seems there could be a distinctive new line in British cop shows emerging. The common factor is that these shows express the ambivalence felt by the public about the police as an institution, an uneasy combination of dependence, distrust and distaste. Things have come a long way since Dixon of Dock Green.