Boris Johnson has called on the UK to negotiate a new "pared-down relationship" with the European Union.
The London Mayor said Britain should remain in the single market but pull out of the political union.
The UK should form an "outer-tier" of the EU with countries like Norway and Switzerland, he said in a speech.
And a referendum should be held with the question: "Do you want to stay in the EU single market as renegotiated? Yes or No?"
He added: "And if people don't think the new relationship is an improvement, then they will exercise their sovereign right to leave the EU."
Mr Johnson urged Prime Minister David Cameron to change tactics in his dealings with Britain's EU partners.
"I don't understand why we continually urge the eurozone countries to go forward with this fiscal and political union, when we know in our hearts that it is anti-democratic and therefore intellectually and morally wrong."
In a question and answer session after the speech at financial news service Thomson Reuters, he said the euro had been "nightmare" for its members, and predicted: "It will eventually blow up but I wouldn't care to bet on when."
He said Britain needed to "maximise the benefits of EU membership and the single market without being kicked out" and insisted other EU countries would accept such a proposition.
He said many of Britain's European partners already believed it was "sliding towards the exit" - and his "minimalist strategy" was in the UK's best long-term interests.
"We should use the opportunity of the Treaty changes - perhaps over the banking union - to convene an inter-governmental conference in which we bring Britain's membership in line with what people want," he said.
David Cameron is due to make a major speech on Europe before the end of the year, amid growing calls from Conservative backbenchers for a referendum on Britain's relationship with the EU.
Mr Johnson, who has previously backed an in/out referendum, said the government had an ideal opportunity to fundamentally renegotiate its membership.
He said "As the governments of the eurozone go forward with treaty changes that materially affect this country - using EU institutions, our institutions, to create an economic government of Europe - then we should seize that moment to ask the British people to define themselves and their future in Europe.
"I think I have a pretty good idea what most commonsensical people want from our relationship with the EU."
Among the areas where Britain needed more control, he argued, were free trade, "to make sure that other countries can't stitch things up against British goods and British business", monetary policy, tax policy, and "less bureaucracy and less intrusion by Brussels into seemingly every aspect of our lives".
"We would like the EU to focus on completion of the single market, where there are still absurd barriers in everything from architecture to the legal profession," he added.
Britain wanted to be "friends" with other EU nations, he said, but added: "We want a relationship in which we are not endlessly made to feel bad for not sharing every doctrine of the euro-religion."
He said these goals could be met if the government changed tactics.
He added: "We could construct a relationship with the EU that more closely resembled that of Norway or Switzerland - except that we would be inside the single market council, and able to shape legislation.
"Indeed, if that were the relationship then there is every chance that we would be joined in that outer tier by Norway and Switzerland, since both those countries are feeling increasingly frustrated by their lack of influence."