Planned opt-out from EU law and order measures 'threatens Britain's security'

Theresa May has won plaudits among Tory Eurosceptics by announcing plans to return power over criminal justice and policing measures from Brussels to Britain. (Getty)

Britain’s security could be jeopardised and the fight against terrorism and international crime undermined by moves to opt out of more than 130 EU measures on law and order, including the European arrest warrant, David Cameron will be told tomorrow.

The controversial move could lead to criminals heading to Britain in the belief they could escape justice in their home countries, a parliamentary committee has warned. Its intervention has inflamed a growing Coalition row on the issue as the Liberal Democrats insisted that it would not support moves to abandon the warrant system.

Mr Cameron and Theresa May, the Home Secretary, have won plaudits among Tory Eurosceptics by announcing plans to return power over criminal justice and policing measures from Brussels to Britain. They include participation in the Europol agency, the sharing of criminal records and DNA samples between member states, and information about money laundering and passport fraud.

The Government says it would “opt in” for measures it considered to be in the national interest.

But in a scathing report, the House of Lords EU committee hit out at the lack of detail and consultation over the moves – and warned the plan could have “significant negative repercussions for security”.