"Subsidiarity" to British politicians means the return of powers from Brussels to the British government to make decisions and legislate on issues that need not be uniform throughout the European Union such as preventing distortions in the single market.

This key British demand in negotiations with the EU is supported in principle by many EU states and is in line with EU treaties. The problem lies not in the principle but in reaching agreement on what has to be decided at the center.

"Devolution" follows this principle within a nation's boundaries.