Gordon Brown has not ruled out a British referendum on the new EU treaty being negotiated this week by leaders in Brussels, according to the Europe minister, Geoff Hoon.

On Friday, Downing Street tried to suggest a referendum was out of the question since Britain would never agree to any transfer of powers that justified such a move.

Mr Hoon is close to the incoming prime minister and his position may reflect a view in his circle that he should not be seen to be ruling out a referendum in advance. Speaking on the BBC, Mr Hoon said: "Clearly a judgment has got to be made in terms of what is in the final package. It is important not to prejudge the outcome of the negotiations, but equally we are trying to negotiate an amending treaty - a treaty that is consistent with the treaties that have, in the past, changed the way the European Union works."