They have a strange tendency to run backwards. Why? This documentary on international football referees doesn't say. But it is very diverting nonetheless. They are the sport's lawmen, subject to all the pressure experienced by the stars, but with none of the cash or adulation, and increasingly considered fair game for abuse by internet bile-spewers and even motormouth coaches for whom vilifying the ref – once unthinkable – is now an accepted mind-game technique.

The film follows a group of refs, including Britain's Howard Webb, during the Euro 2008 championship. It shows how these very human and fallible officials nervously await Uefa's judgment on their performance. As in a reality show, only a select few will be invited back to preside over the final knockout matches after the group phase.

There is something compelling and slightly eerie about seeing a match with the crowd-volume turned down almost to zero while we listen in to the audio channel between the referee and his assistants, formerly known as linesmen, communicating via headsets. It gives us a quasi-telepathic access to a tense, internal world, a little similar to Douglas Gordon and Philippe Pareno's Zidane: A 21st-Century Portrait (2006). There is a very funny moment when one referee's assistant starts wittering distractingly in his earpiece about possible bad weather coming in. He is told, in no uncertain terms, to shut up.

In this tournament, Webb gave a penalty against Poland in their group match, and faced extraordinary abuse, cynically (and surely disgracefully) encouraged by the Polish premier Donald Tusk. In the face of this hate campaign, Webb kept his cool, and he – and his sweet-natured and proud dad – emerge as the stars of this film. In its depiction of loneliness, The Referees slightly resembles the Channel Four TV documentary Graham Taylor: The Impossible Job, from 1994.

It is interesting to compare the match officials' style with the grandees of the game. Michel Platini is the breezy, back-slapping, multi-lingual politician in whose presence the refs are as submissive as schoolboys. The legendary Italian ref Pierluigi Collina, he of the billiard-ball head and piercing gaze, is briefly present. In fact, I think Webb and all the other refs are developing the Collina "look": blank, fierce, hard, directional and unresponsive. It is a look you develop over years of ignoring billionaires screaming in your face while you doggedly point somewhere behind them.

Just one ref, and the two assistants, must impose their will on thousands and thousands of people in the stadium. No wonder they come back into their dressing rooms afterwards on a euphoric high. If the place has not been torched to a smoking ruin, they have won.