 The UK had the most opt-outs of any member state, and along with Ireland was the only member to acquire an opt-out of the Schengen Area agreement.It has notable opt-outs from the European monetary union, and individual pieces of European legislation regarding Justice and Home Affairs.It has been suggested that Britain's reservations about European integration, as well as its unique historical position within Europe and stance of remaining less integrated than other EU states, laid the groundwork for the potential that Britain would decide to exit the bloc.