Prime Minister David Cameron said a eurozone banking union should not discriminate against those countries who do not use the single currency.
He told reporters at the EU summit in Brussels that changes within the eurozone affect Britain as they "affect the organisation that we are are part of".
Mr Cameron also reiterated that Britain will not become a eurozone member, adding, "Certainly not while I'm Prime Minister anyway".
More top news
Very warm in the southeast tomorrow
An astronaut on the International Space Station has shared his experiences from outer space in the first Twitter chat from the craft.
Kate is now an advanced diver after passing a Professional Association of Diving Instructors (PADI) advanced open water diver qualification.