Many British soldiers have been killed by roadside bombs, which critics say have taken an unacceptably high toll because the troops have had to track down the Taliban in vehicles, instead of going into combat aboard helicopters.

There have been recriminations, too, about the British troops’ reliance for transportation on aging, poorly protected Land Rovers from the time of Britain’s military involvement in Northern Ireland.

The criticism has come from the opposition leaders in Parliament and retired British commanders who oversaw earlier stages of the Afghan conflict. American generals, too, have spoken privately about the mismatch between Britain’s military commitments and the British forces’ manpower and equipment.

The Americans say this situation has often contributed to decisions by British commanders in the field to back off from confrontations with the Taliban, or yield ground the British forces have lost soldiers in gaining.

But perhaps the most damaging recriminations have come from the families of the dead.

“They continue to allow the army to operate in those ridiculous tin- can Land Rovers when they should have been equipped three years ago with American Humvees,” Tony Phillipson, father of a 29-year-old army captain killed in 2006, told the BBC on Friday. “The Afghan Army has 4,500 Humvees. Why haven’t our soldiers got them?”

Last week, the political consensus fragmented when Nick Clegg, leader of the opposition Liberal Democrats, used a House of Commons speech to say the government should either finance the war properly, giving the troops the force numbers and equipment they need, or withdraw. “We can’t give them the worst of both worlds  put them in harm’s way, but not give them the backing they need,” he said.

It has been an open secret at Whitehall for years that top generals have been frustrated by being ordered to fight the wars in Iraq and Afghanistan, as well as handle overseas peacekeeping commitments, with a budget that is one of the lowest among leading Western nations, at 2.5 per cent of Britain’s gross domestic product.