The UK opt-in
The UK’s right to decide on a case-by-case basis whether or not to opt in to proposals relating to the area of freedom, security and justice (covering issues such as policing and criminal justice) was set out in Protocol No. 4 to the Amsterdam Treaty in 1997, and confirmed by the Treaty of Lisbon in 2009.
The legal issues arising from the UK opt-out are explored in the Committee's 7th Report of 2008-09:
The Treaty of Lisbon also added Protocol No. 36, according to which the UK may, no later than June 2014, decide to exercise a block opt-out from all EU legislation in this area adopted prior to the coming into force of the Treaty. The Government announced in July 2013 that it would exercise the block opt-out and would seek to rejoin specific measures with effect from 1 December 2014.
The Committee has published two reports considering the implications of the block opt-out:
The Committee’s role in scrutinising opt-in decisions
In 2009 the then Government undertook to take into account the views of the EU Committees of both Houses of Parliament on any opt-in decision, provided they were submitted within eight weeks of the proposal being published. These commitments were underpinned by a resolution of the House of Lords, agreed in March 2010; they were endorsed by the new Government later in 2010.
As a result of these commitments, the House also agreed that if, within this eight-week time-limit, the EU Committee made a report to the House on the relevant proposal, recommending that the Government should or, as the case may be, should not exercise the UK’s right to opt in, the Government would provide time for a debate on the report.
The Committee’s reports on opt-ins
The Committee has made the following reports on proposals subject to the UK's opt-in: