The former postal affairs minister Jo Swinson has railed against the “Orwellian” and “duplicitous” behaviour of some civil servants who kept her in the dark about goings on at the Post Office, as she made a tearful apology for failing to expose the Horizon IT scandal. The former Liberal Democrat leader, who held the postal brief in 2012-13 and again in 2014-15 in the coalition government, also said she deeply regretted turning down a meeting with Sir Alan Bates. The Post Office wrongly prosecuted hundreds of branch operators because of apparent financial shortfalls. It has since emerged that the Horizon IT system was unreliable and had bugs, errors and defects. In December 2014, after a Westminster debate about the Post Office and the mounting scandal, Bates sent Swinson a letter offering a meeting “to discuss the issues involved with this matter from the perspective of those it has affected, rather than from those who seem so desperately to be trying to keep the truth from you”. It took more than a month for Swinson to reply with a letter that drew on many statements that had been used before to defend the robustness of the Horizon system. “Quite a chunk [of my letter] was used in previous circumstances,” Swinson told the public inquiry into the scandal. “It is definitely not taking the [Bates] letter as seriously as required. At the time, what I should have done is agree to the meeting with Sir Alan Bates. I really regret that I didn’t and I’m sorry about that. I was being advised not to.” Swinson was in the job when a company of forensic investigators, Second Sight, carried out a review of Horizon and told parliament in July 2013 that its had found “no evidence of system-wide problems with the Horizon software”. She has since said she was misled, and on Friday she frequently expressed anger and frustration at the behaviour of some civil servants and the former Post Office chief executive Paula Vennells during her more than three hours under questioning. Swinson said some of the documents shown to her at the inquiry, some which she had been unaware of, reflected a “cosy relationship” between the Post Office and the Shareholder Executive, which manages government-owned assets and had a member on the board who is supposed to represent its interests. She said she was kept in the dark about numerous issues such as plans to remove Vennells, who in one internal document was described as “not the optimal person” to be leading the company, and reducing the role of Second Sight. “It was Orwellian, frankly,” said Swinson, who also referred to what she felt was “duplicitous” behaviour. “It feels to me the opposite of what civil servants should be doing. It raises serious questions about how ministers can discharge their responsibilities if civil service briefings cannot be relied upon to provide an objective assessment.” Swinson became teary-eyed when asked at the end of the session by Julian Blake, counsel for the inquiry, about how she had contributed to the scandal. “There are various things I wish I had done differently,” she said. “I wish I had pushed more and probed more. Years of anguish could have been saved for subpostmasters. I’m just really sorry, I asked lots of questions but it wasn’t enough.”