Dick Cheney, US vice-president, "waged a guerrilla war" against attempts by Tony Blair, the British prime minister, to secure United Nations backing for the invasion of Iraq.

Mr Cheney remained implacably opposed to the strategy even after George W. Bush, US president, addressed the UN on the importance of a multilateralist approach, according to a new biography of Mr Blair.

The US vice-president, along with the neo-conservatives in the Bush administration, has consistently argued that the US could be constrained by the UN's inability to reach agreement over the need to invade Iraq.