DAVID Cameron has set himself on a collision course with some of his Conservative colleagues after backing a late bid by Liberal Democrat Michael Moore, the former Scottish Secretary, to enshrine in law a pledge to spend 0.7 per cent of Britain's annual income on overseas aid.

Mr Moore has come second in the list to table a Private Member's Bill and has announced he will seek to make it a legal requirement that at least 0.7 per cent of the UK's Gross National Income is devoted to helping poor countries; in line with a United Nations target. At present, this is about £11bn.

With the official support of the UK Government and the Labour opposition, Mr Moore could have a good chance of having the aid pledge enshrined in law.