Ex-army chief says 'funding is insufficient' for military operations

General Sir Mike Jackson warned of an impending crisis in the wake of spending commitments by Chancellor Alistair Darling.

He told BBC Radio 4's Today programme: "I fear there is some sort of crunch on the horizon".

Mr Darling announced an additional £400 million for defence operations in October's Pre-Budget Report, on top of an extra £8 billion for the Ministry of Defence unveiled in July.

The Chancellor hailed the package, representing an annual real terms rise of 1.5 per cent, as the longest period of rising investment in defence for nearly 30 years.

But Sir Mike said it still might not be enough to pay for operations in Iraq, Afghanistan and any potential future strategic engagements.

"That may be true but what is also true - and this is never really grasped - it may not be enough to do the things which we do now and the things which we may have to do in the future," he said.

"It's not enough to say it's been the longest run, it may have been, but is it enough? That is the exam question."

Sir Mike, who quit as chief of the general staff last year, acknowledged British defence spending was already above the European average.

But he insisted such a comparison risked ignoring the UK's "strategic" needs and suggested that Britain's influence in the world could wane.

"The analysis must start in logic from what it is that the UK thinks is its part to play in a very uncertain and difficult world," he went on.

"You've got to get that analysis right because from that then flows the tools you need... to do the job."

He added: "I detect, I fear, some crisis ahead in defence spending, if things go on as they are in terms of what we do, what we might have to do and the money allocated."

Since his resignation, Sir Mike has already criticised the Ministry of Defence's treatment of soldiers, particularly in the standards of pay and living accommodation.

He said today there was a widespread recognition that the conditions of service for army personnel were "not how they should be".

But he played down warnings - fuelled by his successor General Sir Richard Dannatt at the weekend - that morale among troops is low.

Sir Mike said those returning from operations overseas - he cited Afghanistan - exhibited to him a "quiet pride and satisfaction" in their work.