David Cameron will join another EU summit push towards closer economic integration at the latest gathering of EU leaders in Brussels.
The EU is taking more steps towards what is now officially being described as "genuine" economic and monetary union (EMU).
As a non-eurozone member the UK is not directly involved, but Downing Street fears the necessary tighter economic integration and Brussels-based strict supervision and monitoring of banks could undermine the "integrity" of the EU single market - an EU flagship policy which the UK champions.
More top news
Emotional scenes outside Kings Cross as woman who lost her legs in the 7/7 attacks had an unexpected visit from the man who saved her life.
England's Lionesses have landed back in the UK with their heads held high
The Greeks have voted to reject the austerity terms demanded by eurozone creditors - so, what happens next?