The Swedish "No" to joining the single currency has boosted anti-euro campaigners in the UK, a leading Labour MP has said.

In the wake of Sweden's referendum vote against joining the single currency, there has been increased speculation that a British vote on joining the euro will now not take place before the next general election.

And backbench MP Ian Davidson said that the Swedish vote would have an impact on the situation in the UK, despite denials from Downing Street that this would be the case.

"I listened to what Downing Street said and I looked out my office to see a pig flying past," he told ePolitix.com.

"I think that there can be no doubt that if the Swedish referendum had been 'yes' then Downing Street would have hailed this as being of tremendous significance and relevance."

Speaking on Wednesday the prime minister insisted Britain must keep its "options open" on membership of the single currency.

"I see absolutely no reason for this country to say it will foreclose its options and rule out membership of the single currency," Tony Blair said.

But Davidson argued that the poor economic performance by eurozone countries showed why Britain was better off with Sterling.

As chairman of Labour Against the Euro, Davidson has been a leading critic of moves towards British membership of the single currency.

And he warned that the government is facing a further revolt against its decision not to hold a referendum on the proposed constitution for the European Union.

"It's an absolute certainty in my view that there will be no [euro] referendum before the next general election," he said.

"I do however believe that the government will be obliged to give in to those of use who are calling for a referendum on the European constitution.

"I think that their position on this is just unsustainable. I believe that they will be unable to ratify the new constitution without a referendum."

Davidson said that in Britain, as in Sweden, political elites are "out of touch on the questions of Europe".

And he warned Tony Blair against "pressing ahead in the face of overwhelming public opposition".

"The government's row is really with the British people rather than in the party," said Davidson.

"This is something where those of us who are in the minority in the party are clearly in the majority in the country."