PARTS of Afghanistan that British forces fought to secure will fall back into Taleban hands when troops withdraw next year, a security expert has warned.

Col Richard Kemp, a former Colchester Royal Grammar School pupil who commanded British forces in Afghanistan in 2003, warned Taleban fighters would try to use 2014 to give British forces a bloody nose.

Col Kemp was responding to Prime Minister David Cameron’s description of the Afghan invasion as “mission accomplished”.

He said: “Parts of southern and eastern Afghanistan will fall back into Taleban hands when we leave, I have no doubt about that. The casualties the Afghan security forces are taking are far beyond anything we have suffered and what we are asking them to do will not be sustainable.”

Soldiers from the Colchester Garrison completed four tours of Afghanistan – more than any other unit.

Col Kemp said: “The mission has been a success, but successive governments have been afraid to be clear about what the mission was.

“They have been pretending it was about humanitarian aid, but it was always about removing Al- Qaeda from Afghanistan and preventing it from becoming a place for terrorist opportunity against the West.

“We have achieved that objective.

Al-Qaeda no longer operates in Afghanistan to any significant extent.”

Mr Cameron said UK troops could come home next year knowing it was mission accomplished.

About 5,200 British troops are based in Afghanistan, down from 9,000 at the start of the year.