Moves to scale back joint patrols by international troops with Afghan soldiers will have "minimal" impact on the way British forces operate in the country, Defence Secretary Philip Hammond has said.
Nato announced that it was cutting back on joint patrols in response to a series of "green-on-blue" killings, in which Afghan soldiers and police turned their guns on their international mentors, as well as the outrage sparked by an internet video mocking Islam.
But Mr Hammond - who was summoned to the House of Commons for the second day in succession to explain the change - said it was an operational decision by commanders on the ground, which would leave UK operations "substantially unchanged".
He insisted the Government remains committed to its policy of keeping British combat troops in Afghanistan until the end of 2014, when the International Security and Assistance Force (Isaf) will hand over security responsibilities to Afghans.
Some 51 international troops, including nine Britons, have died as a result of "insider attacks" so far this year. At the weekend, British soldiers Sgt Gareth Thursby and Pte Thomas Wroe were killed by an attacker dressed as an Afghan policeman and feigning injury.
Mr Hammond acknowledged that green-on-blue attacks were "sapping public opinion (and) public morale" in coalition countries.
"That is why we are determined to solve this problem, to nip this trend in the bud and make sure we get on top of this," he said. "Huge resources have been put in by both the Afghans and by Isaf to addressing this problem and I am confident we will see a significant improvement over the coming months."
Mr Hammond faced calls from MPs to accelerate the withdrawal of troops, with Labour's former Europe minister Denis MacShane arguing that they should all be brought home by Christmas.
Conservative MP and former soldier John Baron said that the Isaf announcement threatened to "blow a hole in our stated exit strategy", which relies on international troops being able to mentor and train the Afghan National Security Force (ANSF) in joint operations.
Labour accused Mr Hammond of "not knowing his own policy" after he told the Commons that he was informed of the changes to procedures on joint patrols in a video conference with commanders in Afghanistan on Monday afternoon but had to be "reminded" of it when he saw TV reports on Tuesday morning.