Britain would lose its nuclear deterrent for two decades if Scotland votes for independence because it would no longer have the capability to house Trident submarines.
Scottish independence will force the remainder of the UK to abandon nuclear weapons for at least two decades, according to report by MPs published today.
The Commons Scottish Affairs select committee said it would be possible to move Trident submarines and their missiles from their base on the Clyde within two weeks of separation.
However, the construction of replacement facilities south of the Border could take up to 20 years, they said, effectively forcing the UK Government into “unilateral nuclear disarmament”.
The Continuous At Sea Deterrent, whereby at least one of the submarines is patrolling the UK’s shores around the clock, would stop as a result.
The MPs said it was extremely unlikely a separate Scotland would allow Trident to remain permanently, while basing the submarines abroad would be politically fraught.
A possible solution would be a gentleman’s agreement that would allow the UK to continue basing the submarines inScotland while they found a suitable alternative elsewhere and built the necessary facilities.
But, although there are several potential sites in England and Wales, the committee said all have drawbacks that renderthem unsuitable or expensive to convert for the nuclear deterrent.
Devonport in Plymouth has too large a population in the surrounding area to safely store nuclear warheads, MPs said, while the approach to the Barrow naval base in Cumbria is too shallow for the submarines to regularly dock.
Defence ministers told their inquiry they have made no preparations if Scots vote for separation in autumn 2014 and are pressing ahead with plans to move the Royal Navy’s entire submarine fleet north of the Border by 2017.
But the committee urged both the UK and Scottish governments to publish contingency plans for removing Trident before the referendum so voters understand the consequences.
The naval base at Faslane that houses the submarines is on course to employ 7,500 people by 2022, making it Scotland’s largest worksite, while the missiles and warheads are stored at nearby Coulport.
Replacing them south of the Border is expected to cost well in excess of £3.5 billion, a cost the MPs said would be divided between taxpayers in Scotland and the remainder of the UK as part of the separation deal.
Ian Davidson, the committee’s chairman and the Labour MP for Glasgow South West, said: “The full details of how and when Trident would be removed from Scotland and the full consequences of that plan must be worked out before any referendum is held.”