Lib Dem leader Sir Ed Davey has apologised to victims of the Post Office scandal as he accused the Government of using the scandal to attack political rivals.

Sir Ed has faced fresh scrutiny over his role as postal affairs minister in the coalition government, with the major miscarriage of justice in the spotlight thanks to an ITV drama.

Victims of the scandal that saw hundreds of subpostmasters convicted because of faulty accounting software have argued the MP has questions to answer.

He has also faced increased Conservative attacks about his ministerial role between 2010 and 2012.

Writing in The Guardian on Thursday, Sir Ed said he is “deeply sorry” for the families who have had their lives ruined by “the greatest miscarriage of justice in our time”.

“As one of the ministers over the 20 years of this scandal, including my time as minister responsible for postal affairs, I’m sorry I did not see through the Post Office’s lies – and that it took me five months to meet Alan Bates, the man who has done so much to uncover it,” he said.

He said that the Post Office gave him “categorical assurances” about Horizon, which were “lies”.

“The Post Office is owned by the Government but not run by it, so the official advice I was given when I first became a minister in May 2010 was not to meet Bates,” he said.

“He wrote again urging me to reconsider, and I did then meet him that October. But he shouldn’t have had to wait.

“When Bates told me his concerns about Horizon, I took them extremely seriously and put them to the Post Office.

“What I got back were categorical assurances – the same lies we now know they were telling the subpostmasters, journalists, Parliament and the courts.”

He said that the incident was an opportunity to make “big systemic changes” that would prevent something like the scandal from ever happening again.

However, he said that this opportunity was being missed, with the Government instead using the scandal to deflect criticism from themselves and onto political rivals instead.

“Over the past decade we have seen this form of politics gaining momentum,” he said.

“The Trumpification on the right of the Conservative party. The mindless attacks from some dutiful Tory columnists. The paid ads spreading disinformation and fake news.

“The subpostmasters deserve far better. That starts with overturning their convictions now – more than four years after the high court exonerated them – and properly compensating them quickly – not leaving it to the Post Office’s complicated, slow and inadequate schemes.”