LONDON (Reuters) - For British opponents of the European Union, Greece's turmoil offers an opening: the chance to tempt voters away from what they cast as a crumbling European project, before a looming referendum on Britain's EU membership.
Greeks voted against the terms of a bailout on Sunday, delivering one of the biggest blows to Europe's monetary union since the euro was launched in 1999.
"The European Union is dying before our eyes," said Nigel Farage, leader of the UK Independence Party, an anti-EU party which won 12.6 percent of the vote, but just one seat, in Britain's May 7 general election.
"We can see support for the EU's dream of a United States of Europe fading fast. An outdated European Union has been found out and rejected emphatically by young Greeks."
Richard Tice, a businessman who is helping fund the British 'Out' campaign, told Reuters the Greek vote would make it easier to make the case that membership was bad for EU states.
"The case for Brexit is strengthened by these events," he said. "The euro is beginning to unravel, yet still EU institutions and their supporters want to impose further punishment and austerity on the Greek people."
"This tragedy merely highlights why the UK must leave the EU as soon as possible so we can be back in charge of our own trade agreements, and our own laws."
Britain, the EU's second biggest economy and home to the bloc's main financial centre, has had an ambiguous relationship to the EU for decades, securing opt-outs from some of its policies and a rebate on some of its contributions. It is by far the biggest EU economy to have rejected the euro.
Opponents say the bloc saddles British business with too much regulation, and its right of free movement has brought an unsustainable wave of migrants from poorer and slower-growing EU countries. Supporters say access to the common market is vital for Britain's trade and global influence.
Prime Minister David Cameron, whose Conservative Party has been divided over Europe for decades, has promised Britons a vote by the end of 2017 on whether to stay in.
He says he would prefer to stay, but only if he can negotiate reforms, including more power to restrict welfare benefits for new migrants from other EU states and guarantees of the clout of EU members that do not use the single currency.
Such is the resonance of the Greek crisis, that even one of the senior members of the British "In" campaign, Roland Rudd, said it was now "time to let Greece go".
Nevertheless, privately some British opponents of the EU accept that if Greece leaves the euro and descends into chaos, it could remind British voters of the danger of leaving the EU.
"If Greece leaves and then burns it might not be the best poster boy for an exit," one senior British Eurosceptic told Reuters, asking that he not be identified while discussing the campaign's strategy. "But if the crisis continues to bubble, it will continue to make the EU look like a basket case."
Opinion polls show British voters are divided and that views on the EU are volatile: YouGov polls show that in 2011 a clear majority wanted to leave the EU, while now they show around 44 percent would vote to stay and 38 percent would vote to leave.
If Greece does drop out of the euro, the turmoil could disrupt Cameron's attempt to renegotiate with European leaders.
Still, some Conservatives said the shock could make European leaders more receptive to Cameron's attempt to renegotiate.
"It puts Britain in a very strong position to argue for an arrangement that gives much more flexibility to national parliaments and governments," London mayor Boris Johnson, a potential successor to Cameron as Conservative leader, said on the eve of the Greek vote.
"I think most people, the majority of Brits, will be instinctively very wary of pulling out of something they have been members of for a long time."
Reporting by Guy Faulconbridge; Editing by Peter Graff