Successive Westminster governments have deceived the public by pretending that Trident is a British bomb when it’s actually American, according to a new expert report.

Trident missiles are rented and collected from the US navy, their targeting and communications systems depend on US software and satellites, and their arming and firing systems are made in the US, the report says.

The code words needed to detonate UK warheads are also produced in the US, it claims. In extreme cases, it warns that the US could locate Trident submarines and shoot down their missiles in flight.

The Ministry of Defence argues that the system remains "operationally independent" and say the report is wrong.

But lead author of the study Dr Dan Plesch, the director of the Centre for International Studies and Diplomacy at the University of London., told the Sunday Herald: “The British public have been lied to for decades by an establishment that dare not tell them the truth.”

“This report demonstrates that there is no British bomb, and that Trident is an American system that the Americans can prevent Britain from using independently.

"So the Parliament in London is discussing spending tens of billions of pounds on something that does not exist.”

Westminster is due to debate and decide upon the UK government’s £167 billion plan to renew Trident tomorrow.

Renewal will be opposed by the Scottish National Party and some Labour MPs, but looks likely to be given the go-ahead.

But Plesch, who has researched nuclear weapons for decades, pointed out that the UK did not have national control over Trident.

“Our report shows that 50 years ago the Conservatives handed strategic sovereignty in defence to Washington in a far more concrete way than it ever was to Brussels,” he said.

His report says that the US could “use its formidable anti-submarine warfare capability and knowledge of British operations to hunt for the British submarines and use its dozens of anti-ballistic missile systems on its navy’s vessels to shoot down British Trident missiles.”

It points out that submarines have to collect Trident missiles from a US naval port in Georgia under a “lease-purchase” arrangement.

“The UK makes use of US satellites to target Trident and US communications facilities to contact the submarines,” it says.

“The arming, fuzing and firing system in the UK Trident warhead is manufactured in the US.”

The hardware and software for the unique authorisation code for detonating warheads are produced in the US.

The report concludes the UK has not been an independent nuclear weapons power for decades.

“There may be other reasons for investing in Trident, but preserving an independent nuclear weapons capability to meet unforeseen worst case threats is not one of them,” it says.

John Ainslie, coordinator of the Scottish Campaign for Nuclear Disarmament and a co-author of the report, argued that the US knew all the secrets of the UK’s Trident system.

He said: “It is naive to assume that Britain can really start World War III without Washington’s approval.”

The report was, dismissed as “wrong” by the Ministry of Defence.

“Our continuous at sea deterrent is completely operationally independent,” said a ministry spokeswoman. “The deterrent remains secure, capable and credible, and only the Prime Minister can authorise the firing of these weapons.”

According to the MoD the command and control system was “fully independent” and decision-making and the use of the system were “entirely sovereign to the UK”.

The MoD was backed up by John Gower, its former assistant staff chief responsible for nuclear weapons.

It was “simply preposterous” to suggest that a Trident missile could be shot down after it was launched, he said, “The US cannot prevent a launch, it cannot prevent any target within range from being selected and it cannot interdict the missile once launched.”