Police call for EU arrest warrants to be retained

The officers have already won the backing of Justice Secretary Kenny MacAskill, who said Ms May was "jeopardising the administration of justice in Scotland".

Scottish police have captured at least 60 men and women wanted by courts north of the Border since the warrants, which can be served anywhere in the European Union, were introduced in 2004.

Offenders brought to justice include Marek Harcar, the Slovakian killer of Moira Jones, 33, in Glasgow's Queen's Park in 2008. He was seized in Bratislava before being jailed in Scotland for 25 years.

The Home Secretary, under pressure from the Eurosceptic wing of her party, earlier this month signalled the UK Government would opt out of a whole block of police and justice co-operation agreements finalised at the Lisbon Treaty in 2009, including one guaranteeing European arrest warrants.

However, the threat put her immediately at odds with Mr MacAskill and Scottish police chiefs.

One senior detective, speaking anonymously, said: "This will have very considerable implications for law enforcement in Scotland. It will not alter the fact we would continue to track people down overseas, but it could make it more and more difficult to extradite them to Scotland for offences they have committed here because we will have lost one of our main tools."

The detective was backed by the Association of Scottish Police Superintendents.

However, Eurosceptics south of the Border claim the EU-wide warrants are a threat to what they called "Britain's common-law system of justice", although this ignores Scotland's separate legal framework.

The number of people extradited to and from the UK, and the speed at which they are transferred, has jumped dramatically since European warrants were introduced. This has caused anger among Eurosceptics, who argue British citizens may be facing unfair trials abroad and UK law enforcement agencies are wasting time chasing "wheelbarrow thieves" from Poland.

Ms May is understood to be facing opposition from Liberal Democrat colleagues within the UK Coalition Government. She has until June 2014 to decide whether to carry out her threatened opt-out.

She may, reports suggest, opt out of Lisbon Treaty justice agreements only to opt back in to some of them.

A report from Conservative MP Dominic Raab today admitted half of the 130 "laws" on justice co-operation agreed at Lisbon were of "practical law enforcement merit", but insisted none was valuable enough to outweigh what he saw as a loss of UK democratic control over supranational EU institutions.

This echoes previous remarks made by Ms May. Earlier this month she said: "It is in the national interest the Government has taken this decision. The Government is clear we do not need to remain bound by all of the pre-Lisbon measures.

"Operation shows some pre-Lisbon measures are useful, some less so and some are now entirely defunct."

Ms May and her officials have argued extraditions would be possible without a European arrest warrant – as they were before the instrument was introduced, under international treaties signed before the UK joined the EU. That has not satisfied Mr MacAskill. In a parliamentary answer last week, he said: "Irrespective of whether that is possible, however, those arrangements would not be as satisfactory. The actions and attitude of the UK Government towards Europe are jeopardising the administration of justice in Scotland."

Recent examples of European warrants being used include the extradition of Scots-born maths teacher Jeremy Forrest, who is alleged to have run away with a 15-year-old pupil to France.

A European warrant has also been issued for one of the suspects in the killing of Kevin "The Gerbil" Carroll, who may be hiding in Spain. Scottish police are also acting on substantial numbers of warrants issued by European nations, including, for example, a Pole accused of forcing a child into having sex.