Woking MP Jonathan Lord raised the alarm over potential flaws in Fujitsu’s Horizon technology as early as 2010.

As Mr Lord became increasingly active on behalf of his constituent Seema Misra – who was wrongly convicted of false accounting and theft – he wrote to Ed Davey, then Post Office Minister and now Sir Ed, leader of the Liberal Democrats, noting a “surprisingly large number of similar cases where sub-postmasters have been dismissed by the Post Office”.

Mr Lord asked: “Is there a chance of an independent investigation into the Horizon system to establish conclusively whether sub-postmasters can be confident that the computer systems that are in place are there to support them?”

The then-Mr Davey, who was Post Office minister from 2010 to 2012, responded two months later with apologies for the delay in replying.

While noting that he could not intervene in Mrs Misra’s case, which had by now been determined, the letter spelled out the Post Office position on Horizon.

“Whilst the JFSA [Justice for Sub-postmaters Alliance which Mr Davey had by now met] blames the Horizon system for the financial discrepancies and shortages which have led to a number of sub-postmasters having their contracts terminated and subsequent court action, Post Office Ltd continues to express full confidence in the integrity and robustness of the Horizon system,” it read.

“They base this on the fact that Horizon has been operating for 10 years and typically processes 230 million transactions a month from over 30,000 counter positions in nearly 12,000 post office branches.”

Mr Lord continued to argue the case for an investigation, notably in a broadcast hosted by Nick Wallis, the journalist widely acknowledged to have led the mainstream enquiries into the scandal.

In February 2011, interviewed by Mr Wallis, Mr Lord called for “a full investigation... we need absolutely independent double-checking of the Horizon computer system... but I think also... if discrepancies are shown up within a subpostmaster systems – I think that needs looking into.

“I think our postmasters need to be able to contact the Post Office in the knowledge that things will be looked at in a fair, balanced and compassionate way. Peoples’ livelihoods are on the line here.

“They... almost certainly have invested thousands, if not tens of thousands, of pounds in their businesses and if they don’t feel secure in going to the Post Office and saying ‘Look, there’s a discrepancy here, I need help’... rather than thinking the Post Office... is going to pounce on them, and potentially take them out of the business they’ve worked so hard to build up and put so much money into, then you can understand why they feel worried and why that side of things needs looking at.”

Mr Wallis concluded the interview by saying: “Unfortunately no-one from the Post Office was available to be interviewed this morning.

“However it is worth reiterating that the Post Office says it has ‘complete faith’ in its Horizon IT system and says there is ‘no evidence whatsoever pointing to any fault’ with its technology.”

Mr Lord spent the next decade pursuing an investigation which would finally take shape in the ongoing inquiry led by Sir Wyn Williams.

Sir Ed has said recently he was lied to “on an industrial scale” by the Post Office.

The last word, though, must go to Mrs Misra, finally exonerated in 2021. 

“As I await full and proper compensation, I would like an apology from the Post Office, from Fujitsu, and also from the former Post Office Minister, Sir Ed Davey MP, to whom my MP, Jonathan Lord, wrote on my behalf on October 25, 2010 asking for an independent investigation into the Horizon system but whose request was refused.

“Jonathan has relentlessly pursued justice and the truth over the course of the past 13 years.”