The EU Treaties as amended by the Lisbon Treaty provides for the first time a Treaty base for the return, as well as the increase, of powers. Either would in all likelihood require a Treaty amendment. However, many Eurosceptics believe that the repatriation of EU powers is not possible, while others point to the difficulties the UK would have obtaining the approval of the other 26 Member States to any such Treaty change.
The Conservative Party election manifesto in 2010 stated: “We will work to bring back key powers over legal rights, criminal justice and social and employment legislation to the UK. The Prime Minister, David Cameron, has said that the Government is looking into which elements of the Treaty it intends to repatriate, and has hinted at opportunities to seek repatriation at the time of any forthcoming EU Treaty amendments to settle the eurozone crisis. So far there have been no concrete proposals, but references to tackling the Working Time Directive. The Deputy Prime Minister, Nick Clegg, has been opposed to Conservative proposals, particularly regarding labour law.
In the area of criminal justice the EU Treaties already provide the UK with a mechanism for opting into EU measures or not.