THE Ministry of Defence (MoD) faces a more than £10 billion "black hole" in its equipment budget if Scotland becomes independent, according to SNP sources.

The amount is the equivalent of the two massive aircraft carriers currently being built on the Clyde.

The former Defence Secretary Phillip Hammond set out plans last year to spend £160bn on defence 'equipment and equipment support' over the next decade.

But losing the contribution of Scottish taxpayers would see that cut amount dramatically.

SNP sources say that an analysis of official figures suggests that it might be as much as £13.44 billion.

Last night a spokesman for the MoD said that ministers would not "pre-negotiate the details of independence ahead of the referendum".

Angus Robertson, the SNP Westminster leader and defence spokesperson, said that the figures pointed to the need for co-operation on defence issues between the UK Government and an independent Scotland.

He said: "(These figures) make clear for the MoD that joint procurement and cross-border co-operation following a Yes vote not only makes sense, but will be inevitable.

"Where it provides value for money and meets the specific needs of Scotland and the rest of the UK - of course they would be encouraged."

He said shared arrangements to maintain conventional defence capabilities made obvious sense. Last night a spokesman for the MoD said: "The UK Government is not planning for Scottish independence and cannot pre-negotiate the details of independence ahead of the referendum."

He said: "As set out in the Defence Scotland Analysis Paper, an independent Scottish state could not come close to replicating the level of defence and security that comes from its place within the UK, protected by the full range of UK defence capabilities and benefiting from the manpower, bases and military equipment that the Union provides."