Post office operators whose lives have been ruined by the Horizon scandal could be exonerated under plans being considered by the government, Rishi Sunak has said. The prime minister also confirmed that Alex Chalk, the justice secretary, could strip the Post Office of its powers to prosecute after more than 700 branch managers were wrongly handed criminal convictions. It follows a national outcry over the treatment of post office operators between 1999 and 2015 after faulty Fujitsu software made it appear as though money was missing from their outlets. This week, an ITV drama has highlighted the scandal and heightened demands for the government to take action. Hundreds were jailed or left bankrupt and at least four people took their own lives. Most victims have not received compensation. Asked whether the justice secretary was looking at plans to exonerate the victims or take away the Post Office’s ability to prosecute, Sunak said: “The justice secretary is looking at the things that you’ve described. It wouldn’t be right to pre-empt that process, obviously there’s legal complexity in all of those things, but he is looking at exactly those areas.” In an appearance on BBC One’s Sunday With Laura Kuenssberg programme, he added: “Everyone has been shocked by watching what they have done over the past few days and beyond and it is an appalling miscarriage of justice. “Actually seeing it and hearing about it again just shows what an appalling miscarriage of justice it is for everyone affected and it’s important that those people now get the justice they deserve.” Chalk is looking at potential ways for the Post Office to be stripped of its role in the cases of operators who are seeking to appeal and overturn their convictions, it is understood. According to the Sunday Times, this includes whether the Crown Prosecution Service could take over, which may make it easier for convictions to be quashed. To date, 93 convictions have been overturned and, of those, only 27 people have agreed “full and final settlements”. A source told the Sunday Times that Chalk had long held concerns about the ability of some arm’s-length bodies to mount private prosecutions, as well as the low rate of successful appeals among post office operators. Even after the Horizon computer system was found to be defective, the Post Office has in recent years opposed a number of appeals by operators. Earlier this week, ITV began broadcasting Mr Bates vs the Post Office, a four-part drama charting the scandal and the fight for justice by wrongly prosecuted branch owner-operators. Fifty new potential victims have contacted lawyers this week, including five who wish to appeal against their convictions. Victims of the scandal are “traumatised”, a former post office operator has said. Lee Castleton, who was forced into bankruptcy after being pursued through the courts for hundreds of thousands of pounds in Post Office legal costs, said: “The victims are traumatised. It has been a long time of 25 years, and £135m has been paid to some of the victims, but we have had £150m-plus paid to lawyers. “These lawyers are putting lots of pressure and it is difficult. The schemes are difficult. “We are just normal run-of-the-mill people. We have legal people with us but it is so difficult and it is like a war.” “Why would anybody put the Post Office and DBT [the Department for Business and Trade] in charge of recompensing the victims?” said Castleton, who was played by the actor Will Mellor in the drama. It is not known how much cash was paid back for imaginary shortfalls but so far £151m has been paid in compensation. Operators claimed tens of millions of pounds wrongly clawed back went into Post Office profits. The Post Office is under criminal investigation over “potential fraud offences” committed during the Horizon scandal, the Metropolitan police have confirmed. Officers were “investigating potential fraud offences arising out of these prosecutions”, for example “monies recovered from subpostmasters [operators] as a result of prosecutions or civil actions”, Scotland Yard said on Friday evening. The Met is also investigating two former Fujitsu experts, who were witnesses in the trials, for perjury and perverting the course of justice. There are also growing calls for Paula Vennells, who served as chief executive of the Post Office between 2012 and 2019, to be stripped of her CBE. Last night a petition demanding she lose the honour had garnered more than 760,000 signatures.