Brown takes hard line to reassure voters on limits of the new treaty

Gordon Brown has claimed the European Union would rule out further integration for 10 years after EU leaders approved a new treaty.

At the close of his first European summit as Prime Minister, Mr Brown said the Government would veto any further changes to the EU's internal workings until after 2017. He claimed the backing of other EU members for his decision to challenge one of the Union's founding principles – "ever-closer union".

A decision on a new mission statement for the EU will be taken by EU leaders in December. Several other countries agree that the "navel-gazing" debate about the EU's institutions in recent years has damaged the 27-nation club.

But some refused to go as far as Mr Brown. Jose Socrates, Prime Minister of Portugal, which holds the EU's rotating presidency, said: "Obviously, this treaty is not the end of the story. It has no end."

Nicolas Sarkozy, the French President, agreed that the current treaty would be "the last for a long time".

But he said France has a "very considerable agenda", including closer defence co-operation, for its spell in the EU chair in the second half of next year.

Mr Brown also moved to water down plans by France for an EU "group of wise men" to consider the EU's goals for 2030. He wants its remit to exclude further changes to EU institutions and closer co-operation on defence and foreign affairs.

The Prime Minister's hard line against further integration is designed to reassure British voters that the current treaty will not be another step towards a federal superstate. He told a press conference at the close of the Lisbon summit yesterday he had won agreement that Portugal would consult EU members about a statement of priorities switching the agenda to globalisation and a declaration "ruling out further institutional change for many years".

The treaty was approved in the early hours of yesterday morning after the leaders met last-minute demands by Poland, which wanted more voting clout, and Italy, which won an extra seat in the European Parliament.

British officials said Mr Brown had to intervene to protect one of Britain's four "red lines" – an independent foreign and defence policy – being watered down. This held up agreement for half an hour but most of the wrangling involved Poland and Italy and Britain's negotiating position was not under serious threat.

The new treaty will be formally ratified by each country and signed by EU leaders in December. If approved, it will take effect in January 2009.

It will streamline the EU's decision-making, create a High Representative for foreign policy and a slimmed-down European Commission. Attention now switches to getting the Bill implementing the treaty through Parliament, when Mr Brown will come under renewed pressure for a referendum. The Conservative Party leader, David Cameron, said the refusal to seek the approval of voters was a "denial of democracy".

He added: "We will fight for a referendum. Gordon Brown made a promise to hold a referendum on the EU Constitution. This treaty is almost exactly the same as the Constitution and they have broken their promise."

But the Tory leader faces trouble from 39 Tory MPs who have signed a Commons motion calling for a referendum "before or after ratification". The Tory Eurosceptics have accused the leadership of a "betrayal" because it will not promise to renegotiate the treaty.