British scientists find evidence of deadly sarin in Syria

British scientists have found positive evidence of deadly sarin gas on samples of cloth and soil from the Damascus suburb believed to have been targeted by forces loyal to Syrian president Bashar Assad.

The UK's confirmation of poison gas use will further fuel calls for action against Assad at the G20 summit, where host Vladimir Putin has agreed to put Syria on the agenda for talks over dinner tonight.

Deputy Political Editor Chris Ship reports from St Petersburg: