EVERY fortnight an aeroplane carrying Polish policemen touches down at an airport in southern England. Waiting for them each time is a glum band of 20 or so handcuffed men who are to be flown back to face trial in Poland. Extradited prisoners are normally transferred on ordinary commercial flights, but a surge in the number being sent from Britain to Poland means that now a fortnightly “Con Air” service is being laid on by the Polish authorities.

Astonishingly, Poland now accounts for more than half of all Britain's extraditions to Europe (see chart). The number of transfers grew from four in 2005 to 186 in the first nine months of 2008. That is about ten times the number being sent to Ireland, despite the fact that Irish migrants easily outnumber Poles in Britain. What explains this sudden plague of hardened criminals?

A look at the charge sheet suggests that they may not be so hard after all. The crimes for which people have been extradited include “theft of a chicken”, “theft of a piglet” and “theft of a cupboard door”. Whereas most countries are happy to put minor offences on hold until the suspect re-enters the country, Poland requests extradition for almost any crime, however petty. Some of its eastern neighbours take a similarly finicky approach.

Britain has to take the requests seriously because of the European arrest warrant, which since 2004 has allowed courts to order the arrest of suspects anywhere in the European Union. The warrant has accelerated the process of extradition and made it harder for border-hopping criminals to evade justice. But, like other legal innovations passed in the wake of the attacks on America in 2001, it has become more widely used than expected. Britain's High Court ruled in October that it could not stop the extradition to Romania of a man wanted for stealing ten chickens.

Pressure groups such as Fair Trials International worry about the standard of justice in some of the countries to which suspects are being fast-tracked. The trivial requests are also wearing thin with the British police. Fugitives are tracked down by the Serious Organised Crime Agency, an outfit designed to bust international crime syndicates, which now finds itself a partner in the war on poultry pinching.

In 2008 Britain sent a delegation to Poland to plead for a let-up, but to no avail. In November a meeting of EU members in Brussels again tried to forge a compromise, fruitlessly. The Poles say they are constitutionally bound to pursue every offender. Others say that Poland uses more discretion at home, where its own resources are at stake.

The number of extraditions looks set to grow. In April Britain will join a technologically whizzy pan-European information-sharing scheme, which will replace the current system of faxes and phone calls. The Home Office reckons it will mean that British police have to make about three times as many extradition arrests as they do now. Processing the extra traffic will cost £17m a year even before police and court-staffing costs are factored in.

Surprisingly, dissent among British politicians is muted. The opposition Conservatives are wary of kicking off an argument about Europe within their own ranks, and the Liberal Democrats are supportive of the scheme, partly because it was their European Parliament grouping that pushed the arrest warrant through in the first place. For now, Britain will remain shoulder-to-shoulder with Poland in the crusade against chicken rustling.