The government has acceded to calls to put the inquiry into the Post Office scandal on a statutory footing – but several questions are likely to be left unanswered for the wrongfully convicted sub-postmasters.

Business minister Paul Scully, who last month resisted demands for a full public inquiry, today confirmed the government would extend the existing inquiry under the same judge and widen its scope and terms of reference.

Scully said the inquiry will not just deal with the failings associated with Post Office Ltd’s Horizon IT system, but also the findings of Mr Justice Fraser from the Bates judgment and the recent Court of Appeal judgment which quashed the convictions of 39 former sub-postmasters. This could include analysis of the involvement of Post Office lawyers in the wrongful prosecutions and the non-disclosure of evidence that might have discredited Horizon.

Announcing the statutory inquiry in parliament today, Scully said: ‘The horizon saga has wrecked lives and livelihoods – we can’t undo the damage that has been done but we can establish what went wrong at the Post Office and ensure something like this is never allowed to happen again.’

The inquiry, which will be led by Sir Wyn Williams, is expected to submit its findings in autumn 2022, although an interim report is expected this summer.

The inquiry will not look into the Horizon group damages settlement itself, albeit the inquiry may examine the events leading to the settlement. Neither will the inquiry be asked to look into whether there should be any binding and enforceable code of standards for private prosecutions.

Several MPs spoke during a debate this afternoon outlining their constituents’ experiences of being in some cases jailed, made bankrupt, losing their home or partner, or even taking their own lives.

It was pointed out to Scully that of the £58m settlement agreed with sub-postmasters, some £46m had gone to pay the victims’ legal fees, which were so high only because the Post Office had defended the case so vigorously. The minister offered reassurances that these costs would be paid back, or that costs of legal representation at the inquiry would be met.

On the subject of compensation, Scully said that was a matter for the Post Office to arrange, and the government would continue to discuss the issue with it.