Cameron pledges more 'family' time off for troops as he flies to Afghanistan

On a surprise trip to Helmand province today, David Cameron said rest and recuperation periods would start from the day soldiers arrived back in the UK - and not include days spent travelling.

Currently leave is counted from the moment personnel are released from the front line and there are often severe delays before they get back to their families, eating into their time at home.

David Cameron addresses British troops from 2 PARA Battle Group in Afghanistan

The Tory leader will make the issue of 'lost leave' a centrepiece of his pledge to restore the military covenant - which guarantees soldiers decent treatment in return for putting their lives on the line.

'I think this is fair for our troops,' he said. 'They should be able to predict how long their leave is going to be rather than having to spend it on an aeroplane and on air bases a long way from home.'

At the British base at Lashkar Gah, Mr Cameron added: 'Today when our servicemen and women end their duties in the heat and dust of Afghanistan or Iraq, their leave starts not when they arrive home but often after several days delay in trying to get home.

'Under our plans, the leave clock would not start ticking until they arrive back on British soil. This is a common sense idea that will make a big difference to the lives of our brave troops and their families.'

With flights home frequently delayed due to ageing transport fleet, troops have complained they can spend large chunks of leave waiting for a plane.

Conservative Party leader David Cameron talks with 42 Engineer Regiment's Captain Julian Mitchell as he visits British troops in Helmand Province

The Ministry of Defence relies on Hercules C-130s and Tristar aircraft and there has been considerable concern over their maintenance, with troops left stranded on occasions for up to two days.

Almost a fifth of flights for servicemen and women flying back from Iraq and 29 per cent from Afghanistan were delayed during 2007-08, according to official figures.

One in ten flights from Afghanistan were delayed for more than six hours.

Solving the problem of 'lost leave' was a key recommendation of the Military Covenant Commission - set up by Mr Cameron and led by Frederick Forsyth and Falklands veteran Simon Weston - to look at improving forces' welfare.

Armed forces minister Bob Ainsworth claimed Mr Cameron had confused troops' post-operational annual leave, which begins when they arrive home or at their holiday destination, and mid-tour rest and recuperation breaks.

He said: 'David Cameron has said that the clock should start ticking for leave when our servicemen and women end their duties in an operational theatre. It does.

'After a six month deployment overseas our forces receive the annual leave that they have missed, plus an additional four weeks of leave which is a sacrosanct entitlement.

'It appears David Cameron confused post-operational tour leave with rest and recuperation, which forces receive during an operational tour and which is determined by military commanders.'

David Cameron serves himself breakfast. During his visit to troops in Helmand Province, he pledged to restore 'lost leave'

Mr Cameron, accompanied by shadow Foreign Secretary William Hague, visited Afghanistan amid growing speculation that the British presence there could grow from 8,200 troops to more than 12,000.

It is the latest attempt by aides to burnish the Tory leader's credentials as an international statesman.

And he lavished praise on UK forces, telling them: 'You've got the support of everyone back home. I think if we weren't here the Taliban would come back and the terrorist training camps would start again.'

Mr Cameron insisted that troops needed more 'recognition' and to be properly supplied with equipment. 'There's also a lot that we have got to do.'

He said there had been "progress" but concerns still existed over the shortage of helicopters and the unwillingness of some Nato countries to play their full part in operations.

British troops have been based in the country since 2001, but have seen particularly heavy fighting against the Taliban insurgency in the past two years after they were deployed in Helmand province.

Two British soldiers were killed last month, taking the total death toll to 116, and the UK casualty rate is now higher than that at the peak of the Iraq War and higher than for the American forces.

Last year, Admiral Michael Boyce, former Chief of the Defence Staff, told the House of Lords that some servicemen on the front line in Iraq and Afghanistan feel they are held in contempt.

'The perception,' he said, with the support of four other recent heads of the Armed Forces, 'is that they don't see themselves as being viewed as important' by this Government.