Boris Johnson has put himself on a fresh collision course with David Cameron by criticising the Prime Minister's position on the eurozone crisis.
The outspoken Mayor of London dismissed suggestions that building a "big bazooka" bailout fund and closer fiscal union between the 17 member states would resolve Europe's economic turmoil, it was reported.
Instead, he claimed, the options were more likely to "exacerbate the problem".
Mr Cameron called for a "big bazooka" injection of cash in October to shore up the single currency amid warnings that it was on the brink of collapse.
In an interview with the Sunday Telegraph, Mr Johnson said: "This idea that if we can find a big enough bazooka, we could blow away the problem by creating a euro government in which there will be shared fiscal responsibility, I'm afraid that really will, in the long term, and probably even in the short and medium term, simply exacerbate the problem. That administration, that economic government will have no democratic legitimacy."
He puts forward alternative solutions, including suggestions that the eurozone could be split into two parts, one containing stronger economies such as France and Germany and the other sweeping up the weaker states such as Greece and Portugal.
Another option would be allowing struggling economies to leave the eurozone and devalue, and then either come back in or stick to their old pre-euro currencies.
"What needs to happen now is an orderly realignment; that's to say, there needs to be either a bisection of the euro into north and south, or there needs to be some way in which, in as tidy a way as possible, countries that simply can't take the consequences of the current alignment, are allowed, effectively, to devalue," he said.
Mr Johnson told the newspaper that installing technocrats in place of elected leaders in ailing Greece and Italy was "completely mad".
The Mayor also reiterated his warnings to the European leaders against pushing ahead with a plan to impose a "Tobin" tax on financial transaction - which would hit the City of London hardest - warning it would be a "hostile act".
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