A former Royal Navy commander has backed the Trident whistleblower William McNeilly and accused the navy of being "out of its depth" on nuclear weapons.

Rob Green, who flew nuclear -armed planes and helicopters for the navy in the 1960s and 1970s, praised McNeilly for being "courageous" and "patriotic" in helping to expose a "dangerous situation" which will get worse if Trident is replaced.

Green is famous for being the nephew of the anti-nuclear campaigner, Hilda Murrell, who was murdered in Shrewsbury in 1984. He is now a co-director of the Disarmament and Security Centre in Christchurch, New Zealand and campaigns against nuclear weapons.

He served in the Royal Navy from 1962-82, flying Buccaneer nuclear strike aircraft and anti-submarine helicopters equipped with nuclear depth bombs. On promotion to commander in 1978, he worked in the Ministry of Defence and was an intelligence officer during the Falklands War in 1982.

In an article for the Nuclear Age Peace Foundation, Green argues that the UK Government's Trident programme has been "discredited" by McNeilly's safety and security allegations. Though McNeilly's claims have been dismissed by the navy, Green points to evidence assembled by the Scottish Campaign for Nuclear Disarmament (SCND) substantiating them.

"This episode has indeed delivered a severe blow to the image of the British submarine service," Green says.

He adds: "My conclusion is that the Royal Navy is out of its depth operating the existing Trident system, starved of resources and trying to get by on the cheap.

''This dangerous situation - which the courageous actions of a patriotic young whistleblower have exposed - can only get worse if the UK submarine service has to take on whatever replacement the US is prepared to let the British have."

Amid severe budget cuts, Trident was seen as a "financially vulnerable irrelevance" by the army and the air force, Green argues. It should be scrapped so that the navy could

"refocus on what it does best: conventional deterrence, protection of maritime trade, and defence diplomacy".

SCND's co-ordinator John Ainslie welcomed Green's intervention as "a damning indictment" of the Trident programme.

He said: "McNeilly's report and other sources show that safety standards on British submarines have slipped below what is acceptable in the US Navy."

McNeilly's dossier alleging that Trident was "a disaster waiting to happen" was revealed by the Sunday Herald on May 17. He handed himself in to the police the following day, and has since been dishonourably discharged by the navy, but not charged with any offences.

His allegations were investigated by the Ministry of Defence (MoD) and rejected as "factually incorrect or the result of misunderstanding or partial understanding". The MoD's response, however, was described by the SNP's former leader, Alex Salmond MP, as "an insult to the intelligence of the general public".

The MoD stressed that neither the operational effectiveness of its submarine-based nuclear deterrent, nor the safety of submariners or members of the public, had been compromised.

An MoD spokesman said: "The naval service operates its submarine fleet under the most stringent safety regime, which is subject to independent scrutiny.''