Post Office: Horizon is robust, says ex-boss of postmasters’ union

David Enright, a lawyer who has represented hundreds of people in connection with the Post Office, said Mr Thomson’s “flat earther defence of the horizon computer system defies credulity”.

Mr Thomson said that the number of sub-postmasters who had been prosecuted was a “tiny percentage” of the 100,000 people who have used Horizon over 25 years.

Horizon is a software system for tasks such as accounting and stocktaking which began to be installed across Post Office branches from 1999.

Sub-postmasters complained about bugs after it falsely reported shortfalls – often for many thousands of pounds – but their concerns were dismissed.

Mr Thomson said the Post Office’s “mishandling of the situation” has been “so catastrophic” for sub-postmasters, the brand and Royal Mail group.

It means that the Post Office has “not been able to defend a robust Horizon computer system”, Mr Thomson said.

He added that the NFSP was not told of bugs in the system by the Post Office.

During questioning at the inquiry on Friday, Mr Thomson’s responses were greeted by astonishment and anger by some sub-postmasters in the room.

When asked by Julian Blake, counsel for the inquiry, why the NFSP had not defended sub-postmasters, Mr Thomson insisted that the federation had argued on their behalf but had not had the funds for a legal defence.

The NFSP has received millions of pounds in payments from the Post Office.

Mr Thomson denied that the association became “too close” to the Post Office or was “flush with cash”.

Mr Head said: “I think his evidence so far shows him for the man that he is. He has shown no remorse, no sympathy, there is absolutely no sign of any apology for his or the NFSP’s part in the scandal and the damage done in this scandal.

“The testimony so far is nothing short of abhorrent.”

The NFSP was a trade union – set up in 1897 by a group of sub-postmasters to help their profession – which was changed into a trade association a decade ago after the Post Office did not recognise the group for collective bargaining purposes.

Mr Thomson was general secretary of the NFSP between 2007 and 2018.

He said: “We worked closely with the Post Office because we both needed to have a successful franchise – that’s the reality.”