British ministers have been accused of covering up a failed test of the Trident nuclear deterrent which saw a missile fly off course and head towards the American mainland.
The unarmed Trident II D5 missile was launched from HMS Vengeance, one of four British nuclear-armed submarines based on the Clyde, off the coast of Florida in June.
The disturbing failure is believed to have happened off the coast of Florida just weeks ahead of a crucial Commons vote on the future of the submarine-launched missile system.
Concerns have been raised at the news blackout imposed by the UK Government in the weeks before MPs approved the £40billion Trident renewal programme in July.
A senior naval source told the Sunday Times that the launch failure set off alarm bells in Westminster.
He said: “There was a major panic at the highest level of government and the military after the first test of our nuclear deterrent in four years ended in disastrous failure.
“Ultimately Downing Street decided to cover up the failed test. If the information was made public, they knew how damaging it would be to the credibility of our nuclear deterrent.
“The upcoming Trident vote made it all the more sensitive.
The Trident missiles, which cost £17million each, have been test-fired just five timesin the past 17 years. The success of the other tests in 2000, 2005, 2009 and 2012 were widely hailed by the Government with video footage from the submarines even released on occassion.
Downing Street yesterday confirmed that the missile test had taken place in June.
It said in a statement that the submarine was “successfully tested and certified” but did not make any reference to the errant missile or whether there had been any threat to public safety.
Labour former defence minister Kevan Jones demanded an inquiry into the claims.
Jones said: “The UK’s independent nuclear deterrent is a vital cornerstone for the nation’s defence.
“If there are problems, they should not have been covered up in this ham-fisted way.
“Ministers should come clean if there are problems and there should be an urgent inquiry into what happened.”
A Government spokesman said: “The capability and effectiveness of the Trident missile, should we ever need to employ it, is unquestionable.
“In June the Royal Navy conducted a routine unarmed Trident missile test launch from HMS Vengeance, as part of an operation which is designed to certify the submarine and its crew.
“Vengeance and her crew were successfully tested and certified, allowing Vengeance to return into service. We have absolute confidence in our independent nuclear deterrent.
“We do not provide further details on submarine operations for obvious national security reasons.”
All of Scotland’s MPs, with the exception of Tory David Mundell, voted against the motion to renew the UK’s nuclear deterrent on the west coast of Scotland during the Commons vote in June.
Labour is split over Trident and the bulk of their MPs backed the renewal of the missile system during last year’s vote while the party’s leader Jeremy Corbyn was one of those who voted against it.
The SNP are united in their desire to scrap Trident and remove it from Scotland with First Minister Nicola Sturgeon describing the missile system as “immoral” and “impractical”.