Britain's foreign secretary, Jack Straw, acknowledges the European draft constitution will have a tough time passing at the European Union summit in Brussels, which starts Friday.

Britain remains optimistic that an agreement on the new EU constitution can be reached, but key issues remain to be resolved.

At a briefing in London Thursday, Foreign Secretary Jack Straw said Britain will continue to fight to retain control over its own form of taxation, its judicial system and its foreign and defense policies.

Mr. Straw called the wording of the draft constitution absolutely crucial, if Britain is to sign it.

"We aim to achieve our objectives, and if we do, then what we will see is that this convention text, far from establishing any kind of federal super-state of fantasy, will actually help to strengthen the role of nation states," said Mr. Straw.

The foreign secretary also reiterated he sees no need for a referendum in Britain, if a draft acceptable to the government is agreed.

"What we are talking about here, however, is an amendment to existing treaties, which, as the House of Lords committee themselves have said, an amendment to existing treaties, that is the practice of it, and a consolidation of the existing treaties, which are spread over a number of almost incomprehensible texts, and the net result of this, added all up together, it's House of Lords all party committee, no me, saying this, is that the balance of power is likely to shift from the central union, as it were, to member states," he added. "There is no case for having a referendum."

Asked about a possible veto by Poland, if its voting rights are downgraded, Mr. Straw said he feels there is room for negotiation. Poland and Spain want to keep the voting rights they gained three years ago, and Polish President Alexander Kwasniewski said he would veto a draft giving his country less.

On Wednesday, Italian Prime Minister Silvio Berlusconi, whose country holds the rotating EU presidency, said he would submit a plan to break the deadlock, but he has not yet revealed the formula.