It went on to note that texts were "produced at the last moment" after which there was pressure for agreement.

"The compressed timetable now proposed, having regard to the sitting terms of national parliaments, could not have been better designed to marginalise their role," says the report.

On the substantive issues, the committee argues that the new Reform Treaty - drawn up two years after French and Dutch voters rejected the original EU constitution - is "substantially equivalent" to the constitution.

Although the text indicates that this is not the case for countries that have opt-outs and derogations from parts of the treaty.

This is a key point for UK prime minister Gordon Brown who has rebuffed calls for a referendum on the treaty with the argument that it is sufficiently different to the original EU constitution.

Devoting several pages to the UK's so-called red lines - issues it wanted to secure in the treaty - the report calls into question how legally watertight London's status is concerning the treaty.

On the Charter of Fundamental Rights which will not apply to the UK, the report notes there is some ambiguity on how this opt-out will work with the European Court of Justice.

It points out that other EU laws already in place such as a non-discrimination law may be interpreted more widely by the court once the charter applies in all other member states.

The committee also questions the role of national parliaments in the legislative process suggesting that although the procedure whereby MPs can criticise proposed EU laws contains "a number of small improvements" the "procedure adds very little by way of democratic control over the Commission and the EU institutions."

It strongly objects to wording that says "parliaments shall contribute actively to the good functioning of the union" finding it "particularly serious."

"In our view, these are matters of entitlement, not obligation (…) there should be no

question of being under any legal obligation to do so," says the committee's report.

Brown weakened

The report comes as Mr Brown has been politically weakened by his decision over the weekend not to hold a snap general election, leaving him exposed to accusations of cowardness by the opposition Conservatives.

His weakened stance is likely to give him less leeway to force the EU treaty past reluctant MPs.

However, he is maintaining his combative language ahead of the EU summit next week where member states are supposed to politically agree the document.

On Monday (8 October), he said that if Britain's red lines - in foreign policy, tax, justice and home affairs and the rights charter - are not achieved, "we will either veto it or say there has to be a referendum."