A no-deal Brexit could leave Britain unable to return criminals back to EU states, the Law Society has warned. It said that if the UK exits the EU without a deal it may end up relying on the 1957 European Extradition Convention rather than the European arrest warrant (EAW).

’The British people may not be forgiving if the UK becomes a safe haven for criminals from across the EU27,’ Law Society president Christina Blacklaws said. 'Even where the 1957 European Extradition Convention is still in place, the process is lengthy, costly and taxpayers will end up footing the bill,' she said. 'Switzerland still uses it so the evidence of the system’s defects is there for all to see.'

All current EU member states have signed and ratified the Extradition Convention 1957, but several have repealed provisions implementing the convention, replacing  these with the EAW.

'Under the convention, extradition arrangements with the EU would again become a political decision, with the involvement of the Home Office,' Christina Blacklaws added. 'It would also create problems with Ireland as that’s one of the countries which has repealed legislation – they would have to amend their domestic law as would a string of other EU27 countries, which might not be a political priority for them in the wake of an ill-tempered exit.'

A number of EU states including Germany, France, Czech, the Netherlands, Slovenia and Slovakia would have to change their constitutions in order to allow extraditions of citizens to a non-EU country. 

'Losing the EAW when we leave the EU would also make it more difficult to apprehend people who have committed a crime in the UK and have fled abroad,' added  Blacklaws. 'The most recent case is the EAW issued for Alexander Petrov and Ruslan Boshirov, the Russians accused of the Salisbury poisoning: if found in any country of the EU, they could be arrested and sent to Britain.

'But this would not be possible under the 1957 Extradition Convention and in any case the time it takes to extradite under the convention is 20 times longer than under the EAW,' Blacklaws said.