Prime Minister David Cameron insisted Tuesday that Britain could continue its Libya operations for \"as long as is necessary\", and expressed irritation at warnings from the military that it is overstretched. In a leaked briefing paper, Air Chief Marshal Simon Bryant, the deputy head of the Royal Air Force (RAF), warned its ability to carry out future missions would be under threat if Britain\'s involvement in Libya extended past the summer. Last week First Sea Lord Admiral Mark Stanhope, the head of the Royal Navy, also warned that the armed forces, slimmed down by budget cuts, would have to make tough choices if the Libyan campaign lasts more than six months. At a press conference Tuesday, Cameron showed his impatience with the remarks, saying: \"There are moments where I wake up and read the newspapers and think, \'Look, tell you what, you do the fighting and I\'ll do the talking.\'\" But he said he had spoken to the head of the army and the first sea lord, and \"they are absolutely clear that we are able to keep up this mission for as long as is necessary, and that time is on our side, not on (Moamer) Kadhafi\'s side\". Cameron said \"the pressure is turning up all the time\" on the Libyan leader, citing desertions from the regime and continued pockets of resistance in the west of the country, where Kadhafi\'s forces remain in control. \"I am absolutely confident that we can keep this pressure up, we can maintain this mission for as long as is necessary. Our allies are equally staunch,\" he said. The premier added that he held regular meetings with military chiefs on Libya, the latest on Monday, and the mood was \"hugely enthusiastic about what we are doing and about our abilities to bring this to a conclusion\". In a briefing paper for lawmakers obtained by the Daily Telegraph newspaper, Bryant, the air force\'s head of combat operations, said missions in Afghanistan and Libya were together placing a \"huge\" demand on resources. Bryant described morale as \"fragile\", with many areas \"running hot\" as defence cuts brought in by Cameron\'s year-old coalition government take effect. \"Two concurrent operations are placing a huge demand on equipment and personnel... Should Operation Ellamy (Libya) endure past defence planning assumptions the future contingent capability is likely to be eroded,\" he said. A week ago the navy chief issued a similar warning, saying: \"If we do it longer than six months we will have to reprioritise forces.\" Britain has been one of the chief players in the NATO military alliance implementing a United Nations mandate to enforce a no-fly zone and protect civilians in Libya as Kadhafi attempts to crush a rebel uprising.