FORMER business secretary Sir Vince Cable told the Horizon IT inquiry today that he accepts responsibility for oversight during the scandal where “clearly there was a policy failure.”

The former leader of the Liberal Democrats told the inquiry he “hadn’t the faintest idea” the Post Office was privately prosecuting subpostmasters.

Sir Vince, business secretary between 2010 and 2015, apologised to victims of the Horizon scandal who were “so grievously let down” and said he needed to share “some responsibility for the fact that this happened on our watch.”

He told the probe that problems with Horizon “barely came across my desk,” adding: “When they did it was usually in a very uncontroversial way.”

In his witness statement to the inquiry, Sir Vince said: “These abuses occurred under a large number of ministers in Labour, coalition and Conservative governments and we all share some responsibility for the fact that this happened on our watch.

“I accept my share of that responsibility and apologise to the victims for the fact that they were so grievously let down.”

Counsel to the inquiry Jason Beer asked: “When you say that you accept your share of responsibility, what are you accepting responsibility for?”

Sir Vince replied: “General oversight of the department and this was an area of the department where, clearly, there was a policy failure.”

Asked to what extent the former secretary of state was responsible for oversight of the Post Office’s private prosecutions, Sir Vince said: “On a practical level, I hadn’t the faintest idea that this was happening.”

More than 700 subpostmasters were prosecuted by the Post Office and handed criminal convictions between 1999 and 2015 as Fujitsu’s faulty Horizon system made it appear as though money was missing at their branches.

Hundreds of subpostmasters are still awaiting full compensation.