Soldiers of the 5 General Support Medical Regiment know that at any time one of those bullets could come their way. They also know time is running out for their injured comrades.

This is the kind of horrific situation which brave medics of the Fulwood-based 5 General will face in conflict-torn Afghanistan from the end of this month.

This week, in Preston, the 'enemy ambush' is just a rehearsal. Soon it could be all too real.

Their crucial role over the six month tour will be to supply medical support to various units and perform potentially life saving primary treatment on injured troops.

For many this will be a first deployment to Afghanistan, while others are veterans of past tours.

Sgt Marcus Durber, from Leyland, joined the Army 12 years ago and has been part of the 5 General for just over a year.

A stalwart of deployments to Bosnia, Kosovo, Sierra Leone, Northern Ireland, and – in 2004-5 – Afghanistan, he knows what to expect.

He said: "I think the guys want to get there, get done and come back in one piece. I'm always apprehensive when I go on tour.

"You never know what you're facing out there, so to be blase about it is a bit naive."

Sgt Durber has been married 10 years but says his family accept that the Army is his life.

"We talk about me going away, but my wife knows it is what I want to do," he added.

Cpl Steve Tee, 26, has been in the regiment for 18 months.

He said: "There is definitely apprehension. For some people this is their first tour, and for it to be Afghanistan is a pretty big thing.

"It is natural to be apprehensive and even scared."

Pte Daniel Smith, 19, joined the 5 General in 2005. He said: "I'm apprehensive but looking forward to going more than anything.

"I'm a young lad, I've already been to Iraq and now I'm going to Afghanistan. They are the two major conflicts in our time, so I'm quite excited. It's what I joined up for."

Since 2001 when, British operational involvement in Afghanistan began, 78 troops have been killed. It is clear the bravery and dedication of the 5 General will be vital.

Cpt Simon Bunn, responsible for administration and discipline in the regiment, said: "We know from past tours, and it has been proven, that the aid and assistance casualties get early on is successful in saving lives."