David Cameron has laid bare his frustration with forces chiefs questioning the sustainability of Britain's military commitments, telling them: "You do the fighting and I'll do the talking."
The Prime Minister was forced to insist that the mission in Libya can be maintained for as long as necessary after the concerns of the RAF's second-in-command were leaked.
Air Chief Marshal Sir Simon Bryant said operations in Afghanistan and Libya were together placing a "huge" demand on resources.
In a briefing paper for politicians, he said the RAF's ability to respond to future emergencies will be curtailed if the mission in Libya continues beyond the summer.
Last week head of the Royal Navy Admiral Sir Mark Stanhope questioned the sustainability of current military operations, saying the Government would have to make "challenging decisions" if the Libya mission lasted more than six months.
Asked about the latest intervention today, Mr Cameron told a Downing Street press conference: "There are moments when I wake up, read the newspapers and think: Well look, you do the fighting and I'll do the talking."
Mr Cameron insisted that Chief of the Defence Staff General Sir David Richards and Admiral Stanhope, who was hauled into Number 10 for his comments last week, are "absolutely clear that we are able to keep up this mission for as long as is necessary".
The Prime Minister said: "Time is on our side and we will keep going with this; and the pressure is turning up all the time. I think you can see that with the desertions from Gaddafi's regime, from the pressure he is under in the west of the country where pockets of resistance are growing, and growing in strength and challenging his authority.
"So I'm absolutely confident that we can keep this pressure up. We can maintain this mission for as long as necessary. Our allies are equally staunch, and we are growing in strength in terms of the transitional national council in Benghazi. We will continue working with them to bring this to a happy conclusion.
"I'm very content of the support I'm getting from Britain's military; they are performing magnificently."
He insisted that when he had spoken to airmen, morale and enthusiasm for the job was "extremely high".
But in comments obtained by The Daily Telegraph newspaper, Air Chief Marshal Bryant said morale is "fragile" and that many areas are "running hot", as the coalition's defence cuts appear to undermine the efforts of air crews.
Air Chief Marshal Bryant also raised concern about the length of the Libya operation which has dragged on longer than many observers expected as Colonel Muammar Gaddafi has clung to power.
"Two concurrent operations are placing a huge demand on equipment and personnel," he said.
"Should Operation Ellamy (Libya) endure past defence planning assumptions the future contingent capability is likely to be eroded."
He also said morale in the RAF was being hit by cuts, including thousands of job losses and a pay freeze.
"Morale remains fragile. Although fighting spirit remains positive, this assessment will be challenged by individual harmony targets as Operation Ellamy endures (after September)," he wrote.
"There is decreasing satisfaction with the remunerative offer, and allowances cut and the pay freeze continues to bite."
Referring to last year's strategic defence and security review, he wrote: "The impact of SDSR continues to undermine the sense of being valued. There is concern over the perceived lack of strategic direction which is restricting confidence in the senior leadership."
Liberal Democrat MP Sir Menzies Campbell, a member of the Commons Foreign Affairs Committee, said: "First the Navy, now the RAF: defence decisions are coming home to roost. You can have increased defence commitments and cuts but you can't have both at the same time."Reuse content