Gordon Brown sought to blunt the main Tory attack on the new EU reform treaty yesterday by promising to put any further transfer of power to Brussels to a Commons vote.

The Prime Minister promised a new “lock” on giving up national vetoes in the face of demands by David Cameron that he “let the people decide” on the treaty agreed last week in Lisbon.

Delivering a Commons statement after the summit, Mr Brown insisted he had negotiated a deal that defended Britain’s national interest. He repeated that he was not bound by previous pledges to hold a referendum on the defunct EU constitution.

However, his efforts to counter calls for a plebiscite were undermined by the Irish Prime Minister, who criticised him for “running away” from giving voters a chance to express their views. Bertie Ahern, whose country is the only state committed to holding a referendum, attacked other EU leaders in an interview for being too afraid to make the case for Europe. “I think it’s a bit upsetting . . . to see so many countries running away from giving their people an opportunity,” he told the Irish Independent.

“If you believe in something . . . why not let your people have a say in it. I think the Irish people should take the opportunity to show the rest of Europe that they believe in the cause, and perhaps others shouldn’t be so much afraid of it,” he added.

Mr Ahern’s intervention will delight the Conservatives who harried Mr Brown over his claim that the reform treaty was different in kind from the EU constitution. “This treaty gets rid of the veto in 60 areas, including energy, transport and self-employment law. You’ve given up on the veto but you say it’s OK because you’ve got rid of the [EU] motto. Well I’ve got a motto for you: let the people decide,” Mr Cameron mocked.

The Tory leader was speaking after Mr Brown had set out his arguments on each of the treaty’s most contentious elements, insisting in each case that Britain had won a good deal.

He first denied that the Charter of Fundamental Rights would enable the European Court of Justice in Luxembourg to rewrite British law, insisting that British courts were protected by a special protocol. “This legally binding protocol ensures that nothing in the Charter of Fundamental Rights challenges or undermines the rights already set out in UK law. Nothing in the charter extends the ability of any court — European or national — to strike down UK law,” he said.

On the proposed pooling of sovereignty in scores of justice and home affairs powers, Mr Brown said he had ensured that Britain had the flexibility to adopt those in its interest but reject those that were not.

He said that he had successfully resisted attempts to undermine the intergovernmental nature of EU foreign policy-making and had protected a British national veto on social security. He sought to blunt Conservative objections that the new EU rules allowed for the extension of qualified majority voting (QMV) without the need for further treaties with a pledge that MPs would be given a vote on every proposed surrender of a national veto.

“To ensure that no government can agree without Parliament’s approval to any change in European rules that could, in any way, alter the constitutional balance of power between Britain and the European Union, we will make a provision in the Bill that any proposal to activate the mechanisms in the treaty which provide for further moves to QMV — but which require unanimity — will have to be subject to a prior vote by the House,” he said.

Confirming that he intended to rule out further European integration for the next decade he said: “I can confirm that not just for this Parliament but also for the next, it is the position of the Government to oppose any further institutional change in the relationship between the EU and its member states.”

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