His words are embarrassing for Mr Blair, who pressed for Mr Barroso to become Commission president despite objections by other European leaders. A No 10 spokesman insisted the rebate was not negotiable, saying: "Our position remains the same. The rebate is fully justified and is not up for grabs." The Conservatives criticised Mr Blair's handling of negotiations. Dr Liam Fox, shadow foreign secretary, said: "There must be no question of any challenge to the rebate.