A Royal Navy submariner who exposed a catalogue of alleged security failings around the Trident nuclear programme is facing jail after promising to hand himself in to police on Monday.



Able Seaman William McNeilly, 25, went on the run after claiming that Britain’s nuclear deterrent was a “disaster waiting to happen” in a report detailing 30 alleged safety and security breaches.

He wrote that security lapses at the Faslane naval base on the Clyde, where he is based, meant it was only “a matter of time before we’re infiltrated by a psychopath or a terrorist”.



Brendan O’Hara, the new SNP MP for Argyll and Bute, which includes the Faslane base, said that he would be writing to the defence secretary Michael Fallon to call for an immediate inquiry in McNeilly’s claims.

The 19-page report, which was published online, triggered an immediate investigation by the Ministry of Defence as police and Royal Navy chiefs tried to track down the submariner.

McNeilly, who is understood to have been overseas when the dossier was published, was due to return to the UK on Monday afternoon and hand himself in to the police.

In a statement published on his Facebook page, the 25-year-old said he had moved between countries and changed location every day since going on the run, but that he now “lacks the resources to remain undercover”.

He wrote: “I’ve tried my best over the past year, and I’ve finally achieved what I set out to do. I set out to gather as much information as possible, as fast as possible, inform you and the government before getting caught, then hand myself into the police. There’s nothing I can do from prison; whatever happens now is up to you and the government.”

McNeilly now faces a substantial jail term if he is prosecuted under the Officials Secrets Act 1989. In 2012, Royal Navy petty officer Edward Devenney was jailed for eight years for offering classified nuclear submarine information to MI5 agents posing as Russian spies.

An online petition against his prosecution has amassed more than 1,000 signatories since it was launched on Sunday.



On Facebook, McNeilly gave the impression of an ordinary 25-year-old who enjoyed socialising with friends and watching popular TV series including Game of Thrones and Breaking Bad. His brother, Aaron, wrote on the social network that no one had heard from McNeilly since last Thursday when he left home to go to the airport.



In the report, titled The Secret Nuclear Threat, and published online alongside a picture of his UK passport and Royal Navy identity card, McNeilly said he wanted “to break down the false images of a perfect system that most people envisage exists”.



He described Trident as a “broken system” and said the focus should be on “peacefully removing the threat” and that Britain was heading for “catastrophe” if security was not improved on the nuclear submarines.

McNeilly, a newly qualified engineer who said he was on patrol with HMS Victorious from January to April, described bags going unchecked and said it was “harder getting into most nightclubs” than into control rooms, with broken pin code systems and guards failing to check passes. “All it takes is someone to bring a bomb on board to commit the worst terrorist attack the UK and the world has ever seen,” he wrote.



McNeilly accused navy bosses of covering up a collision between HMS Vanguard and a French submarine in the Atlantic Ocean in February 2009.

The Royal Navy’s Trident-class nuclear submarine HMS Vanguard . McNeilly, accused navy bosses of covering up a collision between Vanguard and a French submarine in the Atlantic in February 2009. Photograph: PA

At the time, Ministry of Defence officials played down the incident and said the Vanguard had sustained only “scrapes”. But McNeilly said a navy chief who was on board at the time told him afterwards: “We thought, this is it – we’re all going to die.”

The more senior submariner allegedly told McNeilly that the French vessel “took a massive chunk out of the front of HMS Vanguard” and grazed the side of the boat. Bottles of high-pressured air came loose in the collision, he claimed, and the British submarine had to return slowly to Faslane to prevent them from exploding.

McNeilly also raised concerns about a number of his fellow seamen, including one whose hobbies he claimed were killing small animals and watching extreme pornography. Another submariner, whom he named only as “Pole”, had threatened to kill two fellow navy personnel and was routinely aggressive, McNeilly claimed.

He described how HMS Vanguard’s missile compartment doubled up as a gym, leading to potentially disastrous mishaps when seamen dropped weights near the boat’s missile firing system.

McNeilly said he raised these and other concerns through the chain of command on multiple occasions, but that “not once did someone even attempt to make a change”.

The whistleblower also revealed that there had allegedly been a fire in the missile compartment when the vessel was in harbour. He claimed the blaze was sparked by overheated cables setting light to stacks of toilet roll. “The chief said if it had been at sea there would’ve been about 50 dead bodies on three deck because of the amount of people struggling to find an emergency breathing system,” he claimed.

The McNeilly revelations prompted another former Royal Navy sailor to speak out about security lapses in the service. Euan Bryson, 25, a communications specialist who served on the HMS Ark Royal and HMS Illustrious, said McNeilly’s allegations “rang true”.

Bryson, who was also based at Faslane for two years before he left the service in 2013, said a shipmate routinely used a blue bank card to get past security into base after losing his Royal Navy identity card on a night out.

“My biggest concern is the security element. In my entire time I never once had a bag searched,” he said. “I made my thoughts clear when I served and when I handed in my resignation. The chain of command system has failed.”

Bryson said there was “manning issues” across the board meaning that relatively junior employees were often tasked to do jobs they did not have the security training or clearance to carry out.



Ministry of Defence officials have launched an investigation into his claims but also sought to downplay their significance. A Royal Navy spokeswoman said the service disagreed with McNeilly’s assessment and described the report as containing “a number of subjective and unsubstantiated personal views”.



But McNeilly stood by his leaks. Writing on Facebook, the 25-year-old said he had anticipated that Royal Navy chiefs would go on the offensive rather than tackling the safety and security issues he raised.

“Security at the site must [be] heightened immediately whether you make the transition to nuclear disarmament or not. Responding by downplaying a report because there’s lack of seniority, acting like your security system is impenetrable and your aged system is still in excellent condition for sailing, is not an adequate response,” he wrote.

He also gave an insight into his time on the run, claiming to have used counter-surveillance techniques and false aliases to avoid detection. He added: “I have had a few suspicious run-ins along the way such as: someone spending 3 hours trying to into my room without knocking (lock the door with the key in it = best security ever), someone trying to get me down an alley and someone coming over and touching my laptop in public, to see what I was doing.”

A Ministry of Defence spokeswoman said earlier on Monday that the Royal Navy was working with the police to track down McNeilly as it was concerned about his “whereabouts and wellbeing”.

The spokeswoman said it was right for the allegations to be investigated but that the publishing of the report did not pose a security risk. She added: “The Royal Navy takes security and nuclear safety extremely seriously and we are fully investigating both the issue of the unauthorised release of this document and its contents.

The naval service operates its submarine fleet under the most stringent safety regime and submarines do not go to sea unless they are completely safe to do so.”