UK troops could come home early

Mr Hammond said there was “a bit of rethinking” about soldier numbers after military commanders reported that Afghan forces were taking on the “lion’s share” of the combat role.

Prime Minister David Cameron has repeatedly said he is keen to avoid a “cliff-edge” on troop withdrawal in 2014, the date when all UK combat forces are due to be out, but insisted the decision should be based on Afghan progress.

Mr Hammond said he had been privately pushing “for keeping force levels as high as possible for as long as possible” earlier this year. But he said military commanders were “surprised by the extent to which they have been able to draw back and leave the Afghans to take the lion’s share of the combat role”.

He added: “I think there is a bit of a rethinking going on about how many troops we do actually need.

“There may be some scope for a little bit more flexibility on the way we draw down, and that is something commanders on the ground are looking at very actively.”

Around 500 British troops are due to fly home by the end of this year, leaving a further 9,000 to return by the end of 2014.

Mr Hammond added: “I think that the message I am getting clearly from the military is that it might be possible to draw down further troops in 2013, whereas six months ago the message coming from them was that we really need to hold on to everything we have got for as long as we possibly can.

“Talking to senior commanders you get a clear sense that their view of force levels is evolving in light of their experiences.”

The Defence Secretary insisted that Britain would not be “spooked” by the run of “green on blue” attacks, in which Afghans have turned on international troops.

He added: “We have to be clear why we came here in the first place. I believe very clearly that if we are going to ask British troops to put themselves in the firing line, we can only do that to protect UK vital national security interests.

“We can ask troops who are here to help build a better Afghanistan, but we cannot ask them to expose themselves to risk for those tasks.

“We can only ask them to expose themselves to risk for Britain’s national security, which is what they signed up to do.”

Downing Street said Mr Cameron had already made clear that he expects to be able to withdraw further troops from Afghanistan in 2013, but said that no decisions have yet been taken.

A Number 10 spokeswoman said: “The Prime Minister made clear during his visit to Afghanistan what the Government’s position is, and that remains the same – that the drawdown will be done in a sensible and ordered way with a staged reduction.”

Meanwhile, a new memorial dedicated to war heroes buried at a Sheffield cemetery was officially opened yesterday.

All the servicemen and women with graves at Shiregreen Cemetery are being honoured by the new monument, which was created following a fundraising campaign led by a mother who lost her son in Afghanistan.

Nicolette Williams, whose son Senior Aircraftsman Christopher Bridge died in Afghanistan five years ago and was buried in the cemetery, was behind the campaign to raise £35,000 for the granite memorial.

Lord Mayor of Sheffield Coun John Campbell said: “There has obviously been a lot of support for Shiregreen Cemetery to have a war memorial, and it will be a lasting memorial for everyone to remember them and thank them for their courage and commitment.”