Britain and France last night voiced united opposition to extending the war against terrorism to Iraq.

At the annual Anglo-French summit yesterday, Tony Blair and French president Jacques Chirac expressed solidarity with the US in Afghanistan but said the war should not be extended to Iraq unless "incontrovertible evidence" emerged linking the country to the September 11 attacks.

But speaking during a visit to Washington, Conservative Party leader, Iain Duncan Smith, said that Britain should support rebels in Iraq in taking a similar role to the Northern Alliance in Afghanistan, a suggestion that Blair has rejected.

Duncan Smith also backed calls by president Bush for Saddam Hussein to allow weapons inspectors into the country and gave his strong backing for American plans for a missile defence shield.

The Conservative leader's arguments are rejected by today's Mail, which says an attack on Iraq would be "a step too far".

"Mr Bush should hold his fire," the paper cautions.

Beyond the immediate "war on terror", both Blair and Chirac hailed the Anglo-French relationship.

Blair said the UK and France had come "closer together" in recent years while Chirac said the relationship had an "excellent quality".