A Post Office lawyer has said there was a “bunker mentality” among staff in relation to the media’s coverage of the Horizon IT system.

Rodric Williams, who joined the organisation as a litigation lawyer in 2012, was asked at the Horizon Inquiry on Thursday about an email sent to the Post Office by journalist Nick Wallis in 2014.

In the email, Mr Wallis asked when was the last time the Post Office did any research into how satisfied subpostmasters were with the Horizon system.

In a response to colleagues about Mr Wallis’s email, Mr Williams said: “We don’t need to do research on Horizon – it’s the system we provide to our agents and require them to use. If agents don’t like it, they can choose not to provide services for us.

“The vast majority of our agents and other users work with it just fine, and we’re not required to bespoke our point of sale accounting system to the whims of each individual agent.”

Mr Williams was asked if it was his view at the time that “subpostmasters could either use Horizon or leave”.

“Yes,” he said.

He was asked if he meant “like it or lump it”.

“Not necessarily,” he said.

“It is the system that is used across many thousands of branches, and I think tens of thousands of terminals.

Post Office Horizon IT scandal
In 2015, Tim McCormack wrote to Post Office CEO Paula Vennells (Anthony Delvin/PA)

“That is the system the Post Office provided.”

However, he said he did not believe there was an “obligation” on the Post Office to do market research on Horizon’s users.

He told the inquiry there was a “bunker mentality” among the organisation’s staff in relation to the media’s treatment of Horizon.

“I don’t know if I can speak for senior management but I do think certainly where I was sitting it did feel a bit bunker mentality, yes,” he told the inquiry.

He was asked if he was in the bunker.

“I probably was, yes,” he said.

Mr Williams was also asked about his attitude towards Tim McCormack, a former subpostmaster who tried to warn the organisation about the Horizon system.

In 2015, Mr McCormack wrote to Post Office CEO Paula Vennells warning her that he had “clear and unquestionable evidence of an intermittent bug in Horizon that can and does cause thousands of pounds in losses to subpostmasters”.

He said it was her “last chance” to accept that “what I have been telling you these last few years is true”.

He invited Ms Vennells to visit a branch with him, so he could show her the evidence.

The email was forwarded to Mr Williams, who told colleagues that they should ask Mr McCormack to send them the information.

“Generally, my view is that this guy is a bluffer, who keeps expecting us to march to his tune,” he wrote in email to colleagues.

“I don’t think we should do that, but instead respond with a straight bat.”

The inquiry also heard that Mr Williams accused the Criminal Case Review Commission (CCRC) of “jumping down every rabbit hole” by asking the organisation to disclose information about bugs in the Horizon system.

The CCRC, which investigates miscarriages of justice, asked the Post Office in 2016 for information relating to bugs in the Horizon system.

Forwarding the request in an internal email, Rodric Williams accused the CCRC of being “directed” to the rabbit holes.

Jason Beer KC said: “It’s that siege mentality again, Mr Williams, isn’t it? Challenges to the Post Office are hostile and must be fended off rather than considered on their merits.”

Mr Williams said: “I think that’s maybe overstating but there’s probably something in that, I think, that’s fair,” he said.

He was asked if he was “paranoid” that others were acting “in concert” with the CCRC.

“I said seemed to be,” he said.

“I didn’t know if these were things they had got to on their own or with prompting.”