Defence officials are considering designating the Scottish home of Trident as sovereign United Kingdom territory, it has been claimed.

Britain's nuclear deterrent is housed at a naval base on the Clyde but the SNP wants rid of the system and Whitehall is looking at alternatives ahead of Scotland's independence referendum next year, according to a Guardian report.

The move would give Faslane the same status as the British sovereign military bases in Cyprus, the newspaper said.

A defence source said: "It would cost a huge amount of money, running into tens of billions of pounds, to decommission Faslane.

"Those costs would be factored into any negotiations on an independence settlement. The sovereign base area is an option. It is an interesting idea because the costs of moving out of Faslane are eye-wateringly high."

Defence Secretary Philip Hammond warned earlier this month that moving the base for the continuous at-sea nuclear deterrent would "cost a significant amount of money" but the Government has always officially insisted it is not working on other options because it expects Scots to vote to remain in the UK.

An MoD spokesman said: "No contingency plans are being made to move Trident out of Scotland. The scale and cost of any potential relocation away from Faslane would be enormous."

Downing Street said Prime Minister David Cameron would not support proposals to designate the Clydeside home of the Trident nuclear deterrent as sovereign United Kingdom territory if Scotland votes for independence.

A Number 10 spokesman said that no such idea had been presented to Mr Cameron or to Defence Secretary Philip Hammond, adding that it would not be a "credible or sensible" course of action.

The Number 10 spokesman said: "This Government has not commissioned contingency plans over Faslane. No such ideas have come to the Secretary of State or the Prime Minister.

"They would not support them if they did. It's not a credible or sensible idea."

Angus Robertson, SNP Westminster Leader and Defence spokesman, said: "This is an extraordinary attempt by Westminster to bully Scotland.

"Neither the people nor parliament of Scotland want nuclear weapons dumped here, and we are clear that Trident would have to be removed as quickly as possible - only a Yes vote next September will empower Scotland to get rid of Trident, and the money saved help build a fairer society and stronger economy.

"A key argument for independence is that Scotland will no longer have to pay for nuclear weapons that we do not want. A No vote, by contrast, means a new generation of nuclear weapons on the Clyde for another 50 years."