Tony Blair has refused at his weekly Commons question time to rule out a referendum on joining the
euro before the next election.
The prime minister said Britain should keep its options open, despite taunts from Tory leader Iain Duncan Smith that his "dreams, schemes and hopes to scrap the pound are utterly wrecked".
Mr Blair was also accused by Liberal Democrat leader Charles Kennedy of "withholding" information in his dossiers on Iraq's weapons - a charge he quickly denied.
Mr Duncan Smith completed the attack on the prime minister by arguing that since Labour had come to power, council tax had gone up "by a massive 70%".
Mr Blair came under fire about the three issues during his weekly question time in the House of Commons.
The Conservative leader focused his attack on the euro just days after Sweden voted "no" in its referendum on whether to join.
Mr Duncan Smith said "the whereabouts of your road show is a mystery - even to your own government".
But Mr Blair insisted there had been about 60 different visits from foreign office ministers during the last few months.
"It is important that we keep the option of joining the single currency open for the reasons I've given," he said.
"The policy you have, which is to close off this option and say 'no' in any
set of circumstances would not be right for the British people."
Mr Duncan Smith then pressed the prime minister to confirm that there would not be a referendum in this Parliament.
Mr Blair replied: "No, I certainly won't confirm that. We should keep our options open because the right test to apply is whether it is in the economic interests of this country.
"We have said we will return to that issue again next year and I see absolutely no reason for this country to say it will foreclose its options and rule out
membership of a single currency."
But Mr Duncan Smith accused: "You're spinning road shows, wasting public money and
legislating for a referendum you don't have the courage to hold.
"Why won't you admit what everybody else knows that your dreams, schemes and
hopes to scrap the pound are utterly wrecked!"
Mr Blair retorted: "We have got to decide what's in our best interests as a country and I happen
to believe that in our best interest we should keep the option of joining the
single currency open - if it's in our economic interests to do so."
On Iraq, Mr Kennedy referred to the recent report by the Intelligence and Security Committee which said the prime minister had been warned by the intelligence chiefs that war in that region could increase terrorism.
He pressed the prime minister to say why he had not "played it straight" with the British people.
Mr Blair said: "All I can tell you if you want it straight is the day we have the foreign policy run by the Liberal Democrats is the day this country really would be at risk."
Mr Duncan Smith returned to the foray later to attack the government's record on council tax, which he said was now costing a typical family £413 more since 1997, with poor pensioners spending £1 per £10 on the tax.
Mr Blair agreed that council tax has risen, but added that the amount of money given to local authorities had gone up by 25%, compared to the real terms cut of 7% under the Tories.
Earlier, Mr Blair sought to rally his increasingly rebellious Labour backbenchers behind controversial measures like tuition fees, foundation hospitals and his reform of public services.
Mr Blair told opponents of the plan to make graduates pay for their courses once they start work that there was no "cost free option", but he conceded there was a debate in the party over the issue.