The head of the Army has warned that any gap between military resources and planned capabilities caused by spending cuts “could become quite dangerous, quite quickly”. Chief of the General Staff General Sir Peter Wall said imposing further efficiencies while the impact of previous deep spending cuts on the armed forces were still being absorbed would be “very disruptive”.

His comments came with the Ministry of Defence under pressure to deliver its share of the £11.5 billion spending cuts across Government demanded by Chancellor George Osborne in his spending review. Defence has some protection in the 2015/16 review, to be unveiled on June 26, with a guaranteed 1% increase in equipment budgets from 2015, but Defence Secretary Philip Hammond has still been asked to find a 5% cut in other spending. However, senior MoD sources claimed a deal with the Treasury was now close that would not involve any further reduction in military numbers or capability.

Sir Peter was interviewed as part of the Britain’s Last War documentary broadcast on Sky News last night. Presenter Jeff Randall asked him: “The forthcoming spending review seems sure to bring further cuts to the defence budget, and the arms budget, leaving a considerable gap between planned capabilities and available resources. How dangerous is that gap?”

He replied: “I think it could become quite dangerous, quite quickly.” He told the programme: “We have got to the point in a number of parts in our set up where we can’t go any further without seriously damaging our professional competence and our chances of success in the battlefields of the future. “It would be a brave claim to say an organisation can never make more efficiencies but we do need the time to let our new structures bed in, for those efficiencies to get delivered. “Imposing more on us now, before the last round of efficiencies have really materialised properly in a balanced way, would be very disruptive.”

David Cameron has hit back over the fears, insisting that Britain’s forces are among the best-funded in the world. The Prime Minister said “difficult decisions” are being taken under the Coalition’s austerity programme and warned that no department is immune from making savings.