Paula Vennells: 5 key moments from Post Office scandal inquiry

Another stand-out moment came when Ms Vennells was asked about the flotation of Royal Mail in 2013.

The Post Office used to be part of Royal Mail but was split off when the then coalition government decided to privatise the UK’s postal service.

The board of the Post Office had become alarmed about potential civil claims for wrongful prosecutions, to the point where it notified the Post Office’s insurers.

Ms Vennells admitted that revelations about possible prosecution failures during the time when Royal Mail was in charge of the Post Office would have been devastating for the privatisation.

Royal Mail director Les Owen had wanted to include a reference to the Horizon IT system in the prospectus for the flotation.

But Ms Vennells admitted that she’d arranged for it to be removed, telling her boss afterwards: “I have earned my keep on this one.”

In fact, she listed keeping Horizon out of the Royal Mail flotation prospectus as one of her “key achievements” for the year.

Edward Henry KC, who is representing some of sub-postmasters at the inquiry, asked that if it had emerged that people were being wrongly prosecuted “it would have threatened to disrupt the flotation”.

“I’m sure that would have been the case,” Ms Vennells said.

But she added that she “had no conversations about any strategy around the Royal Mail privatisation”.

Reporting by Tom Espiner, Tom Beal, Peter Ruddick, Theo Leggett and Dearbail Jordan