David Cameron joins another EU summit push towards closer economic integration on Thursday - observing from outside the eurozone but seeking safeguards for the single market and the City of London.
The latest gathering of EU leaders in Brussels 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 the UK champions.
On Wednesday night EU finance ministers moved closer to agreeing the elements of a eurozone banking union with a single, central supervising body, paving the way for the summit to agree the timetable for introducing the "single supervisory mechanism".
The proposed road map on the summit agenda also includes fixing a deadline for measures on bank "resolution" - how to handle failing banks - and how to set minimum standards for deposit guarantee schemes.
The 15-page report prepared for EU leaders also looks at even greater eurozone fiscal integration, with co-ordination of national budget decisions and economic policies, probably after 2014.
Draft summit conclusions also emphasise the need to help the search for jobs and growth by reinforcing the European single market - the one key EU element Mr Cameron insists must be preserved in any new settlement negotiated between the UK and the rest of the EU.
On the eve of the summit European Commission president Jose Manuel Barroso made clear he felt more integration should not stop at the eurozone. He told MEPs in Strasbourg that agreement on the single supervisory mechanism was crucially important at the summit - the "single most important step for the further deepening and completion of economic and monetary union".
He said it was essential that the summit clearly signalled action via the road map to "guarantee the irreversibility and the sustainability of economic and monetary union and the euro."
The 17-member eurozone area should integrate more quickly and more decisively than the 27-member EU, said Mr Barroso whilst maintaining the "integrity" of the 27-nation single market. He added: "Lastly, creating a deep and genuine EMU will require commensurate steps towards a political union."
Conservative MEP Geoffrey Van Orden, pointing out that Mr Barroso had recently called for a "new direction" for Europe, said: "Instead it is precisely the old thinking that is offered - with 'more Europe' as the answer to every crisis, and with a relentless drive to create a state called Europe - a European Federation - an idea which has no mandate from the citizens of our countries."
UK Independence Party leader Nigel Farage warned about a "clear divergence of political will of the British people and EU centralisers in Brussels".