The court ruled that the Post Office’s actions had amounted to “an affront to the conscience of the court”, having heard how vital evidence was withheld from subpostmasters when they were being prosecuted, and quashed 39 of the 42 convictions.

Subpostmasters were victims of a scandal which saw the Post Office use its private prosecution powers over a 15-year period from 2000 onwards to convict them of crimes including theft and false accounting when its faulty Horizon accounting system showed unexplained shortfalls or discrepancies at branches across the country.

The Post Office has since admitted that the unreliable and flawed computer evidence may have been used to prosecute more than 700 subpostmasters without any police involvement as people were charged and convicted of crimes they had not committed.

Neil Hudgell, of Hudgell Solicitors, helped 32 former subpostmasters clear their names and is also supporting a further 55 to take their cases to the Court of Appeal.

He said: “It is almost impossible to describe the true impact that this scandal has had on the lives of this group of people who had their reputations and livelihoods so unfairly destroyed.

“They are honest, hard-working people who served their communities but have had to live with the stigma of being branded criminals for many years, all the while knowing they have been innocent. It has been an honour to stand by their side and reach this point today.

“The court heard shocking evidence with regard to the Post Office and how it destroyed innocent people. Indeed, given its actions, everything the Post Office has sought to do over the last year or so, whether it be by way of apology and offers of redress, or by talking about a cultural change, completely unravelled when our clients’ cases were heard.

He added: “This has quite rightly been labelled as one of the biggest legal scandals ever in the UK, and that scandal will only deepen should those involved not now finally face a fiercely run investigation into how these prosecutions were conducted, what exactly was known as to the unreliability of the Horizon system when it was being used to ruin peoples’ lives, and whether people acted in a criminal manner.

“Investigations must go from the very top of the organisation to those investigating subpostmasters and forcing them to admit to crimes they had not committed.”

He concluded: “The Prime Minister must also, as a matter of urgency, now convene a judge-led public inquiry, where all those who played any part in this large scale injustice are required by law to appear and be fully questioned under the rules of evidence and held to account for the appalling suffering caused to so many.

“The Independent Review currently underway does not have the powers required. The people we represent have seen the Post Office give excuse after excuse for what has happened almost completely unchallenged, even to this day.

“The time has come now for people at the Post Office who were involved in any way relating to these unsafe convictions to feel the uncomfortable breath of the law on their necks as our clients did.”