Planes axed for aircraft carriers (UKPA) Britain's aircraft carriers will be left without planes for a period because of cuts to the military budget in next week's spending review, Defence Secretary Liam Fox has confirmed. Two former heads of the Royal Navy have warned that a decision to withdraw Harrier jets before the arrival of new Joint Strike Fighter F35s in 2018 would leave Britain unable to fight another Falklands War. Dr Fox confirmed that there will be a "gap" between the phasing out of the Harriers and the US-built F35s coming into service, but insisted that this will not put the Falklands at risk. Britain currently has sufficient basing and over-flight rights to allow it to deploy air power wherever it wants in the world, even without fixed-wing aircraft on board its carrier fleet, he told BBC1's Politics Show. Dr Fox also acknowledged that armed forces personnel numbers would "inevitably... fall a bit" as a result of the defence settlement, which is expected to require cuts of 7-8%. But he declined to discuss reports that the forces could lose a combined total of as many as 20,000 servicemen. Announcements on precise figures will be made in Tuesday's Strategic Defence and Security Review which follows the unveiling of a new National Security Strategy on Monday. The Defence Secretary confirmed that Prime Minister David Cameron had been "extraordinarily helpful" in securing a more favourable settlement for the Ministry of Defence after Chancellor George Osborne's initial demand for cuts of 10-20%. Mr Cameron intervened personally on Friday after military chiefs warned that the threatened cuts could harm Britain's mission in Afghanistan, and US Secretary of State Hillary Clinton took the unusual step of voicing concern publicly about the scale of cuts. Foreign Secretary William Hague said today he had "reassured" the US over Britain's defence spending. He told Sky News he had personally assured Mrs Clinton that Britain "will retain a wide spectrum of military capabilities... and we will be continuing to be a big contributor to Nato and to the collective defence of all Nato nations". Chancellor George Osborne said that the decision to go ahead with building two new Â£5 billion aircraft carriers was the most difficult he had to take in the comprehensive spending review, but said it would have cost more to cancel the project than to keep it.