David Cameron is to convene a secret summit of military experts, ministers and Tory MPs on the war in Afghanistan. The meeting at Chequers this week will also be attended by members of the new National Security Council, including Nick Clegg, the Liberal Democrat leader, William Hague, the foreign secretary, and George Osborne, the chancellor. Government officials insist it is not a precursor to a radical change of strategy. However, insiders say it will be an opportunity for delegates with reservations about Britains mission to voice their concerns, which could pave the way for an earlier exit than previously foreseen. The prime minister is said to be anxious not to prolong Britains commitment in the region any longer than necessary and there is mounting concern over the weekly fatalities. Among those attending are the Conservative MP Adam Holloway, a former soldier who served in Iraq, Bosnia and Afghanistan. He has publicly suggested that the mission is on the brink of failure, and warned that the heavy presence of coalition troops is aggravating the problem in the area. Rory Stewart, a new Tory MP who is a former British Army officer with extensive experience of the conflict, has also publicly voiced his concern, suggesting the mission is doomed. He has publicly questioned the governments key argument for Britains continuing involvement in Afghanistan that it reduces the terrorism threat in Britain describing it as ridiculous. Liam Fox, the defence secretary, who will also attend the Tuesday meeting at Camerons country residence, has called for troops to be pulled out as soon as possible, saying soldiers are not there for the sake of the education policy in a broken 13th-century country, though there is no timetable for withdrawal. Insiders are speculating about a shift in emphasis in the Afghanistan campaign, with less focus on reconstruction and more emphasis on creating the conditions in which the Afghan National Army can take over. In recent weeks Nato has stepped up efforts to mentor senior Afghan personnel. The summit comes as Denis MacShane, the former Foreign Office minister, calls for British troops to be withdrawn. The White House is clearly looking for an exit strategy. We have done our duty. It is time to come home, he writes in an article for The Observer today. (The Sunday Times)