Straw voices his enthusiasm for the Nice Treaty

Jack Straw said yesterday that ratification of the Nice Treaty would send a clear message that Britain was committed to "righting the wrongs of history and reuniting Europe".

But while he supported the agreement on EU enlargement he criticised Romano Prodi, the European Commission's president, for suggesting that the European Union could admit more members without the treaty being ratified by all 15 member states.

Last month, the Irish voted against the Nice Treaty in a referendum. Opening the debate on a Bill to ratify the treaty, the Foreign Secretary told MPs that politicians in Ireland needed time to win over the public.

The Conservatives went on the attack, tabling 14 amendments, including a proposal to subject the entire treaty to a referendum. They voiced objections to extended majority voting in Europe, which would erode Britain's veto; to proposals for European funding of political parties; and sought an inquiry into the proposed European rapid reaction force.

Francis Maude, the shadow Foreign Secretary, said the treaty was unnecessary and rooted in the past. He accused the Government of showing contempt for Irish voters by pressing ahead with ratification.

But Mr Straw rejected Tory claims that the treaty paved the way for a federal European state, insisting that it strengthened the decision-making powers of ministers at European ministerial meetings.

Increasing the use of majority voting would allow Britain to push through reforms against opposition from other European states, he said. He insisted that it would be "absurd" to hold a referendum on the treaty.

When the treaty has been ratified, he added, "we shall have put in place the final institutional reforms the EU needs to be ready for enlargement. British companies will be able to benefit from access to the largest single market for trade and investment in the world." He said: "Enlargement will give us more allies to help counter organised crime, drug trafficking and illegal immigration and it will give us a cleaner environment.

"Passing this Bill is of very great importance and will strengthen Britain's influence at the heart of this Europe of nation states." Mr Straw expressed disappointment at the Irish referendum result but insisted that he would respect the decision. He warned: "We cannot afford to take public support for the EU for granted. The Nice Treaty does not mean the end of the British justice system, a ban on political parties nor an end to freedom of thought and religion. It preserves and enhances the UK's ability to influence decisions and take initiatives for the benefit of our citizens."

Mr Maude described the treaty as a "triumph of old think". He said: "It could have been the moment to bid farewell to the old dogma of one-size-fits-all political integration. It could have been the time to embrace the need for a decentralised and flexible EU. It could have set deadlines for enlargement, which we wholeheartedly support. Sadly none of this transpired."

Mr Maude said the Tories were in favour of enlargement of the EU rather than further integration. He said: "I hope we can have an end to this nonsense that the Nice Treaty is necessary. By agreeing a rigidly integrationist treaty, which the Nice Treaty is, we have actually ­ I say we collectively, we the EU ­ set enlargement back."

Menzies Campbell, the Liberal Democrat foreign affairs spokesman, said: "It is a treaty which justifies neither euphoria nor hysteria."

The Bill's second reading was backed by 385 to 148, a government majority of 237.