(L-R) Air Chief Marshal Sir Jock Stirrup, Chief of the Defence Staff and General Sir Richard Dannatt, Chief of General Staff Photo: PA

Sir Jock said his forces needed as many helicopters as they could get and were “busting a gut” to draft more into service.

His comments are likely to cause more discomfort for Gordon Brown who on Thursday faced a grilling from MPs on equipment and troops after the Defence Select Committee warned a shortage of helicopters was undermining the “protection” of forces.

“In this situation where you have lots of improvised explosive devices, the more you can increase your tactical flexibility by moving people by helicopters then the more unpredictable your movements become to the enemy,” Sir Jock said, speaking in Downing Street after talks with the Prime Minister.

“Therefore it is quite patently the case that you could save casualties by doing that.”

Asked about whether British forces in Afghanistan had enough helicopters, the Air Chief Marshal said there was “no such thing as enough helicopters in an operational campaign”.

“If you are an operational commander you can always do more and do things better the more helicopters you have.

“If I thought we had enough helicopters in Afghanistan frankly we wouldn’t be busting a gut to get the Merlins we had deployed in Iraq ready to go out this time to Afghanistan.

“We need as many helicopters out there as we can get.”

His comments followed those of Gen Dannatt, who set out a “shopping list” of new equipment he wants to protect British forces from bomb attacks in Afghanistan.

The general’s requests, made in a BBC Radio 4 Today interview, are likely to strain further his relations with Labour ministers.

It comes as the Ministy of Defence announced another solider had been killed in Afghanistan, the 185th since British forces entered the country.

Some Labour MPs are privately accusing Gen Dannatt of overstepping his role, but the general insisted he will go on speaking out until he retires next month.

The Prime Minister earlier this year vetoed an Army request to send almost 2,000 more troop to Afghanistan on cost grounds. Gen Dannatt today repeated his call for more troops, suggesting a “short term uplift” in British number for between 12 and 18 months.

Britain has over 9,000 troops in Afghanistan after a “temporary” deployment of 700 more men to cover the Afghan elections next month. The MoD initially said that numbers would then fall back to 8,300, but Gordon Brown has promised to review that plan in the autumn.

Gen Dannatt today told ministers they must keep numbers at least 9,000.

“There is a feeling about that it might come back down to 8,300,” he said. “My observation is that that would be the wrong thing to do. I could not support that.”

Gen Dannatt also suggested that General Stanley A McChrystal, the US commander in Afghanistan, may ask Britain for more troops as part of a review he is conducting.

“If he asks the question, we have got to answer the question,” he said.

Gen Dannatt made clear he would support a rise in UK numbers.

“There may well be a case for a short-term uplift. Our Government would have to confront it if asked,” he said.

After the deaths of 15 soldiers in a 10-day period, the Government is under intense pressure over the equipment and vehicles in use in Afghanistan.

After visiting the country this week, Gen Dannatt said he returned with a list of new requirements.

British forces need more aerial surveillance capability to spot bombs being planted, he said. They also need greater human intelligence capacity to anticipate attacks.

Continuing British deaths from roadside bombs ultimately threaten the entire Western strategy in Afghanistan, he said, by undermining British public support for the mission.

“If we don’t get the tactic battle right, we risk strategic loss.”

Gen Dannatt also raised the possibility that the Treasury may be unable to fund his “shopping list” forcing the Ministry of Defence to find extra money for the Army in Afghanistan by dropping projects elsewhere, especially plans to buy new RAF aircraft and Royal Navy ships.

“If this is really important and the national finances are in such dire straits that we are not going to get more money from the Treasury, the MoD gets £34 billion and we may have to reorder our budget again.”

“That will not be welcome but it may be necessary,” he added.

First Minister Lord Mandelson said that the General’s comments “will be taken very seriously”.

Speaking in Derby, he said: “They will not go without whatever they need to carry out their very important operations in Afghanistan.”

Lord Mandelson said: “I don’t think that General Dannatt is politicising anything.

“He’s speaking up, quite rightly, from the front, bringing first- hand knowledge and experience.

“Ministers, as well as his own colleagues, will be responding quickly.”

And the Business Secretary criticised opposition politicians for politicising the issue.

He said: “For troops on the front line this is the last thing they need.

“They want to know they have the united backing of ministers and politicians from all parties behind their efforts and the huge task they have taken on.

“So I think opposition politicians need to be very wary of politicising a situation like this.

“It’s not needed, it’s not welcome and it’s not a good place to go.”