British Prime Minister David Cameron said on Sunday that he is "perfectly entitled" and "enabled" to block efforts by the European Union to make treaty changes unless other EU partners allow the UK to loosen its ties with the union.
Cameron made the statements on the BBC's Andrew Marr Show and said voters would be offered a "real choice" on the UK's role in the EU at the next election.
The prime minister signaled he is interested in blocking efforts by euro zone countries to make changes to the EU treaty that would alter the rules around the single currency, intended to make it more efficient and effective, reports the Guardian.
All of the treaty changes would require a unanimous vote among members of the EU and a veto from Britain could derail any efforts to increase EU supervision of banks and deficits.
The United Kingdom belongs to the European Union but is not one of 17 nations that use the single currency.
"What's happening in Europe right now is massive change being driven by the existence of the euro," Cameron said. "The countries of the euro, they've got to change to make their currency work - the need to integrate more, they need to make changes to all their systems more."
"What that means is they are changing the nature of the organization to which we belong," Cameron continued. "And so we are perfectly entitled, and not just entitled but actually enabled because they need changes to ask for changes ourselves."
Cameron is expected to make a major policy speech at the end of the month outlining his position of the EU. Many in his Conservative party have called for a voter referendum on membership in the EU but Cameron has so far resisted, saying that being entirely outside of the European Union would not be "right for Britain."