The British military, however, has made it clear that it is overstretched. “We’re at the maximum of what Britain can do in the world,” one source said. Mr Brown, who spent Saturday in Afghanistan reviewing the state of the conflict, is being urged by advisers not to expand the force beyond the 8,400 troops now in place in Helmand province and in neighbouring Kandahar at a major airbase…

When asked about further British troop deployments next year in Kabul on Saturday, Mr Brown replied that nations other than Britain must bear the burden.