Tory MP David Davis on why he resigned from the commitee

The committee met for the first time on Thursday to discuss how the National Changeover Plan unveiled by the prime minister last week might be implemented.

The meeting was conducted in a "business-like" manner according to Liberal Democrat MP Vincent Cable.

But Conservatives refused to have anything to do with the proceedings.

They say the group is designed to make the switch from the pound to the euro an inevitability.

'Tories denying choice'

Mr Brown attacked the boycott in a short Commons debate on EU convergence.

He accused the Tories of "denying choice to the British people" by abandoning meaningful preparations in case the UK was to join the single currency at a later date.

"Their motto is to be unprepared," he said.

Gordon Brown: UK's entry to Euro not a certainty

"We hope that every political party in this House would see the national economic interest in this matter and would have participated in this committee.

"The Conservative Party has so marginalised itself that it won't even participate in the discussions about preparations.

"They are now the runt of a sect of a faction of a once national party."

But Shadow Chancellor Francis Maude protested that the changeover plan was about "edging Britain ever closer to membership in an attempt to close off the option of Britain prospering outside".

He asked what estimate had been made of the conversion cost to business and the taxpayer of joining the euro.

Economic Secretary Patricia Hewitt puts the government's case for preparing

Mr Brown said: "If you sent representatives to the committee, they would look at issues like this."

Mr Brown reiterated that the UK would only adopt the single currency if the euro was successful and in the UK's economic interest.

Francis Maude: Government wasting millions of pounds

Any such move would then have to be agreed by the Cabinet, Parliament and a referendum of the British people.

Mr Maude said the government was so sure that membership would be in Britain's interests that it was ready to commit millions of pounds to preparations on the "arrogant assumption that the British people will want to join it".

He asked: "How can you possibly be so sure when you've not even bothered to estimate the costs, let alone the benefits?"

Lib-Dem warning

However, the Lib Dems accused Labour of not doing enough to get ready for the euro.

Dr Cable said there were gaping holes in the changeover plan

He urged ministers to change the Bank of England's terms of reference to ensure UK interest rates were brought in line with lower levels elsewhere in Europe.

Dr Cable warned of further problems if the government did not begin immediate consultation with business to decide at which exchange rate the UK should join a single currency.