Gordon Brown will be absent from Thursday’s official signing of the EU treaty, but will travel to Lisbon and sign the contentious document after joining “some of” the lunch with other European leaders, Downing Street said on Tuesday.

The prime minister’s spokesman on Tuesday morning refused to say whether Mr Brown would sign the treaty in public. This stance prompted William Hague, shadow foreign secretary, to accuse Mr Brown of lacking political courage and the “guts to [sign the treaty] in public”.