Pat McFadden says he should have questioned Post Office defence of Horizon

The cabinet minister Pat McFadden has told the inquiry into the Horizon IT scandal that he now wishes he had questioned the Post Office more over its “emphatic” defence of its flawed accounting software.

The Labour MP, who is now chancellor of the duchy of Lancaster after helping mastermind Keir Starmer’s election victory, said “wrong” information on the Horizon system has had “terrible human consequences”.

The inquiry has heard months of evidence into the wrongful prosecution of hundreds of post office operators on the basis of false data from Horizon. It called McFadden on Thursday because of his role in the last Labour government as a junior minister with oversight of the Post Office.

McFadden told the inquiry that ministers had no part in overseeing the Post Office’s prosecutions of post office operators, but acknowledged that he wished he had challenged those in charge at the state-owned body who insisted Horizon was robust when concerns were first raised.

The inquiry has called an array of politicians and leaders within the state-owned business who were involved in the scandal. McFadden’s testimony was followed by that of the now Liberal Democrat leader, Sir Ed Davey, who was the postal affairs minister between May 2010 and February 2012.

McFadden’s role was early on as a junior minister, just as the first concerns about Horizon were starting to be raised publicly. He asked the inquiry to consider whether it should recommend creating an inspectorate to oversee bodies such as the Post Office, which are owned by the government but run at arm’s length.

Sam Stevens, a counsel to the inquiry, asked McFadden in detail about the way in which ministers made decisions related to the Post Office. McFadden said ministers had to trust that the information being given to them was accurate.

McFadden said: “The information turns out to have been wrong, with terrible human consequences for some of the people who were here.”

Some of the first warnings of problems with the Horizon system came from MPs and the Computer Weekly magazine in 2009 . McFadden’s department asked the Post Office to respond to those concerns.

“The Post Office kept insisting that the system was robust and fit for purpose,” McFadden said. “If you ask me over the whole story here, of course I wish I had done more to question these responses. I believe if I had, I would have got the same response from the Post Office.”

McFadden said it appeared that at some point the Post Office’s defences of the Horizon system moved “from blind faith to dishonesty”, although he said he did not know when that point was reached.