Differentiated integration

[2]In an attempt to resolve confusion around the many kinds of differentiated integration, Alexander Stubb categorised the mechanism into three distinct concepts: multi-speed, variable geometry, and à la carte.

[3][4] Stubb's initial work can be considered outdated as it does not take into account facets of DI which have more recently been outlined by academics.

[6] Some academic literature includes de facto differentiated integration and informal opt-outs focusing on the different ways member states comply with uniform EU rules,[7] others look at groups of member states forming informal differentiated cooperation.

[10] The main practical strength of differentiated integration is its ability to move negotiations forward in the context of a heterogeneous Europe.

If unanimous agreement must be met, policies may be dictated by the lowest common denominator or be confronted by political deadlock.

Under John Major, the British government did not wish to be part of the common currency nor the proposed social policy in 1992 during the Maastricht Treaty negotiations.

The eventual flexibility offered by other member states and EU institutions regarding these key issues for the UK brought two advantages.

First, it made it possible for the other states to proceed in negotiation, and second, it relieved political pressure from the British government.

[13] This is an example of À La Carte DI where policy specific opt-outs are carried out by an EU member state.

This was mainly due to Italy granting temporary residence permits to migrants who could then move freely within the Schengen area which led France to introduce internal border checks.