Gordon Brown will travel to Portugal to sign the reworked European Union constitutional treaty, but he will not attend the actual signing ceremony for the document, it was confirmed today in a decision that the former Tory leader William Hague called a "ridiculous fudge".

The Prime Minister's attendance at the signing of the controversial EU Reform Treaty in Lisbon on Thursday had been in doubt for several weeks because of a clash in his schedule.

Mr Brown was due to make his first appearance before the Commons Liaison Committee, a heavyweight group of senior backbench MPs, at exactly the same time as the Treaty of Lisbon is being signed by the other 26 EU leaders. "The Liaison Committee must come first," an aide said.

Mr Brown would have faced little criticism at home if he did miss the signing of the Treaty, which replaced the failed EU constitution dumped after its rejection by French and Dutch voters in referendums in 2005.

Although the new treaty dropped elements of the consitution such as an EU flag and anthem critics, including the Conservative leadership, regard it as a repackaged constitution and have been pushing for the referendum promised by Labour before its general election victory in 2005.

But Mr Brown's spokesman, Michael Ellam, confirmed that the Committee has moved the hearing to earlier in the morning, allowing Mr Brown to attend the Lisbon signing.

Mr Ellam said: "There had been some uncertainty about the exact date as to when the treaty would be signed. We have done everything that we can in order to accommodate the Prime Minister’s travel plans to Lisbon and the Liaison Committee have kindly agreed to bring forward the timing of their hearing...so the Prime Minister can be in Lisbon for as much of the day as possible.

"The Prime Minister will be going to Lisbon. He’s not going to make the signing ceremony but will sign the treaty. The Prime Minister will sign it in person."

But Mr Hague - who as Shadow Foreign Secretary has led the Conservative campaign to force the Government to accept a referendum on the treaty - attacked Mr Brown for his dithering and lack of courage.

He said: "Some people say Gordon Brown’s problems are that he isn’t decisive and he lacks political courage. He couldn’t have done more to confirm that than this ridiculous fudge.

"He’s dithered over it for a week and now he decided that he’ll sign this Treaty but he doesn’t have the guts to do it in public. His excuses fool no one: he must stop treating people like fools.

"If he backs the renamed EU Constitution so much that he’s ready to break his manifesto promise, he should at least have the courage to be photographed doing it. If he’s ashamed of signing this Treaty then why doesn’t he honour his election promise and let the British people have their say?"

The Treaty of Lisbon Ceremony is due to start at 11.30am this Thursday. The treaty signing is due at 12.15pm and the family photograph at 1.10pm.

It creates a permanent EU President, a high representative for foreign affairs and a legal personality for the Union, as well as reducing the number of commissioners to streamline procedures in an enlarged EU of 27 states.

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