IT will be very difficult to prosecute disgraced former defence secretary Gavin Williamson under the Official Secrets Act for what was “a political disclosure".

That is the verdict of Clive Ponting, the man who was famously found not guilty of breaching the Official Secrets Act during the 1980s.

Williamson was sacked from his position after being accused leaking secret National Security Council discussions related to plans to allow Chinese state-owned firm Huawei to supply technology for the UK's next-generation 5G network.

READ MORE: Defence Secretary fired by May in row over Huawei leaks

The now former defence secretary swore on the lives of his children that he was not responsible for the leak.

Ponting was charged after blowing the whistle on the correct account of the sinking of the Argentine warship General Belgrano by the Royal Navy submarine HMS Conqueror during the Falklands War.

In 1984, civil servant Ponting sent two documents to the late Labour MP Tam Dalyell, who had repeatedly questioned Prime Minister Margaret Thatcher on the sinking, showing that Parliament was being misled over the Belgrano’s fate.

Dalyell took them to the Foreign Affairs Select Committee chairman Sir Anthony Kershaw who returned them to the Ministry of Defence, after which Ponting was prosecuted under the infamous ‘catch all’ Section 2 of the then Official Secrets Act.

READ MORE: FM says Gavin Williamson leak shows Westminster 'dysfunction'

Speaking exclusively to The National which revealed last year that he had moved to the Scottish Borders and joined the SNP, Ponting said: “There is a difference between what happened to me and this situation.

“My material was unclassified and sent to Parliament, but Michael Heseltine (then Defence Secretary) decided he wanted a prosecution.

“They admitted that the documents were unclassified and were not matters of security or anything like that, it was political embarrassment.

“I sent the documents to Tam who correctly showed them to the Chairman of the Foreign Affairs Select Committee who promptly sent them back to Heseltine and that’s how I was prosecuted.

“No thanks to the judge, the jury decided I was innocent.”

Politics is at the heart of this story, Ponting feels.

He said: “When you look at this Williamson story, it doesn’t seem to me to have very many actual secrets, it’s more of a political disclosure.

“He has not revealed what the problem may or may not be with Huawei, and I doubt very much if many of the National Security Council know the details or understand these matters.

“In my day it wasn’t called the National Security Council, it was the called the Overseas and Defence Committee. It’s the same committee, it’s just been given the American-style name.

“Some of the stuff they discuss will be highly classified. Obviously, I don’t know what was in the Huawei discussions but it seems to me that this is more of a political situation, a political embarrassment than the leaking of an official secret.

“They weren’t all agreed about what they were going to do, and that’s what he has made public.”

Ponting thinks the Williamson leak case will not go to court: “I would find it difficult to believe that it will get into court, because the ‘compelling evidence’ mentioned by the Prime Minister is the fact of the phone call between Williamson and the journalist [Steven Swinford of The Telegraph] and it may be that they can’t track that anybody else spoke to the journalist.

“But that doesn’t prove anything in a court of law, and presumably the journalist will refuse to reveal his sources, and if he does and Williamson denies it, I would not have thought there would be a successful prosecution.

“In the end it is often the political price that is paid, rather than a criminal one, and I think the price is Williamson being unable to resuscitate his political career as I gather he was pretty unpopular before all this started.”