THE UK Government would be forced to give an independent Scotland £7 billion in defence assets - even if it refuses to pay any national debt, an SNP MP has claimed.

Angus Robertson, the party's defence spokesman, said Westminster could not afford to leave the landmass to its northern border undefended.

Alex Salmond has threatened to walk away from any share of UK debt if the pro-UK parties carry through their pledge to block a currency union.

In retaliation, Coalition sources have suggested it could withhold all UK assets - including potentially billions of pounds worth of defence equipment such as fighter jets.

Mr Robertson claimed that threat was hollow.

The MP for Moray said: "It is in the mutual interest of both parties that we have a sustainable solution going forward.

"It seems self-evident that looking from things from a Whitehall perspective, one of the things you are going to be really keen to do is make sure your neighbour on the very same island has the capability to defend 'Northern Britain'."

He predicted that there would be a "grown up discussion" around the more than £7 billion of defence assets to which he said Scotland would be entitled in the event of a Yes vote this week.

He added: "It would make no sense for negotiators in London to want to be difficult about the assets that would provide security for people in the rest of the UK as well, and vice versa."

The Ministry of Defence says that is will not pre-negotiate ahead of the outcome of Thursday's referendum.

But last month Coalition sources suggested that debt and assets could be played off against each other in any separation negotiations. A source said: "If you won't pay the mortgage, why should you keep the house?"

Meanwhile, a former head of the Royal Navy has warned that the world could be more "dangerous" in the event of a Yes vote.

Mark Stanhope, the former First Sea Lord, pointed to what was happening in Russia in recent months.

He said that the SNP's plans to expel the UK's nuclear deterrent from Scotland after independence would make an uncertain world more difficult.

In an open letter to Alex Salmond, he said: "President Putin's recent warning about Russia remaining a nuclear state has reminded us all about the salience of nuclear deterrence.

"Your plans for the removal of all nuclear submarines from Faslane in the event of Scottish independence would add a dangerous period of destabilisation in our nuclear defence posture at a time when the international picture is clearly deteriorating."

lAn independent Scotland would require the unanimous backing of all Nato members if it wants to join the alliance, the organisation's secretary general has made clear. Anders Fogh Rasmussen said that any newly-independent state that wanted to become a Nato member would have to apply to join and then gain the support of all 28 existing member states. An SNP spokeswoman said: "The Nato secretary general has simply outlined the process we are already aware of."