Mr Brown arriving for the Cabinet meeting

Ministers had gathered to hammer out one of the biggest decisions of Tony Blair's premiership as they considered the case for joining the single currency.

Mr Brown emerged from Downing Street to confirm he would announce the Cabinet's decision in the House of Commons on Monday.

He said: "We are all resolved that the decision on the euro must be taken in the national economic interest and it will be the national economic interest that will be the determining factor."

The UK's euro verdict A need-to-know guide At-a-glance

Mr Blair's official spokesman later said: "[The meeting] marked the end of the a very thorough and detailed process which the prime minister, the chancellor and the Cabinet have valued greatly."

Shadow chancellor Michael Howard said it was "depressingly clear" the British national interest would come a "poor second" to faction fighting in the government.

"Whatever gloss Tony Blair and Gordon Brown put on the Cabinet meeting, Labour remain split over the euro referendum," he said.

Ministers have waded through 1,738 pages of Treasury background studies - weighing about a stone - looking into the implications of the UK replacing the pound with the euro.

Mr Brown said all the relevant documents would be published on Monday morning so voters could look at the background to the government's decision.

'Leaked'

The Lib Dems have already complained that MPs are going to get just six and a half hours to read the same documents ahead of Mr Brown's statement.

Deputy Prime Minister John Prescott greets journalists before the meeting

Ministers were tight-lipped as they arrived for the cabinet meeting, ignoring journalists' questions, though Deputy Prime Minister John Prescott gave what seemed to be a rude gesture to the cameras as he entered Downing Street.

It is believed the Treasury's assessment of the euro says that not all its five economic tests have been met - ruling out a referendum on the currency this year.

The big question is whether the final decision will leave open the possibility of a poll during the next two years and ahead of the next general election.

There have been reports that Mr Blair has held sway in that argument.

'Settled view'

Mr Brown is said to favour putting off a poll until after the election - but the prime minister is said to be ready to put off the general election until 2006 to allow for the euro vote.

The UK's five tests Convergence with eurozone Enough flexibility to adapt Impact on jobs Impact on financial services Impact on foreign investment

According to some reports, Thursday's cabinet meeting agenda was extended to include a wider discussion on the UK's relationship with the rest of Europe in response to last week's row over the proposed EU constitution.

The Tories have been calling for a referendum on the plans - a demand vigorously opposed by the government.

And the extension of the cabinet agenda suggests that Monday's announcement on the euro will have a strongly pro-Europe feel in an attempt to appease those MPs who back membership of the euro.

Pro-euro campaigners are bracing themselves for the expected "not yet" decision, a point underlined on Wednesday when many endorsed a 10-point "road map" towards a referendum before the next general election.

'Rhetoric'

The Foreign Policy Centre proposal says ministers should be sent out to campaign for euro membership and legislation paving the way to a referendum should be brought forward.

The plan also calls for measures to encourage fixed rate mortgages such as those available in other EU countries.

Mark Leonard, director of the Foreign Policy Centre, said: "The government have got to stop acting as if euro membership is out of their control.

"Wrapping a deferred referendum in pro-European rhetoric will fool no-one," he said.