Legislation aimed at quashing the wrongful convictions of subpostmasters caught up in the Horizon IT scandal is to be extended to Northern Ireland, the Government has said.

Post Office minister Kevin Hollinrake announced the move, stating it had become apparent that the Northern Ireland Executive “does not have the ability to rapidly address the 26 convictions known to be within its purview”.

Amendments have now been tabled to expand the territorial extent of the Government’s Bill.

Stormont ministers had previously expressed disappointment that the Government had not widened its legislation to include Northern Ireland.

The Post Office (Horizon System) Offences Bill will exonerate those convicted on the basis of the faulty Horizon accounting software.

Northern Ireland and Scotland were excluded from the initial Bill, with the Government having pledged to work with those devolved administrations to find ways for them to expunge wrongful convictions.

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

Mr Hollinrake said: “We always carefully consider the territorial extent of each piece of legislation and are rigorous in our commitment to devolution.

“However, it has become apparent that the Northern Ireland Executive does not have the ability to rapidly address the 26 convictions known to be within its purview.

“It has become clear that postmasters in Northern Ireland could have their convictions quashed significantly later than those who were convicted in England and Wales, which would be unacceptable.”

Affected postmasters across the UK will have the option of accepting a fixed sum offer of £600,000 after their conviction is quashed.

Northern Ireland Secretary Chris Heaton-Harris said: “I am pleased that the Post Office Horizon legislation will be amended to include Northern Ireland.

“I’ve been speaking to Minister Hollinrake, the Northern Ireland First Minister (Michelle O’Neill), deputy First Minister (Emma Little-Pengelly) and Justice Minister (Naomi Long) about this important issue regularly.

“It’s clear that, in the context of a recently restored Executive and Assembly, adding Northern Ireland to this Bill is the best way to deliver justice for the victims as quickly as possible.”

Stormont’s leaders have welcomed the decision, which they said followed representations by the Executive ministers to “ensure that those affected here are treated on the same basis as their counterparts elsewhere”.

First Minister Michelle O’Neill said: “The decision to include sub-postmasters here is the fastest and fairest solution for all.

“This is a prime example of the Executive working together to deliver for people here.

“Those wrongly convicted have already endured years of emotional and financial stress through no fault of their own. They now deserve a swift resolution with their convictions overturned in the quickest and most seamless manner.”

Deputy First Minister Emma Little-Pengelly added: “This is good news for subpostmasters in Northern Ireland who have been wronged by the Horizon IT scandal. Amending the Westminster legislation is the fastest solution including in terms of accessing financial redress.

“I sincerely hope those affected take some comfort from knowing there will be no additional delays in having their convictions overturned.”

Justice Minister, Naomi Long said: “It was always my view that subpostmasters in Northern Ireland should receive equitable treatment in line with their counterparts in other parts of the UK.”

Mrs Long told the Stormont Assembly that it is possible more victims in Northern Ireland may emerge.

She said: “It will not undo all of the harm that has been caused by the original Horizon Scandal, but it will hopefully at least ensure equitable treatment for our constituents.

“One of my fears was that given the experience people have had of the justice system, given the false information that was produced by Horizon, that they may not wish to come forward and reopen that can of worms by going through an administrative process.

“This means that the convictions will be expunged and by a process that will be underpinned by UK legislation, and hopefully, that will be a swifter process, and perhaps more people will come forward but to the best of our knowledge (the number of people affected in Northern Ireland is) 26.”

DUP interim leader Gavin Robinson said: “This was a scandal of breath-taking proportions which has devastated the lives of innocent people in every corner of the UK.

“Ultimate tribute must be paid to those postmasters who stood so bravely from the start and fought back against the onslaught they faced.

“This unprecedented legislation will exonerate those caught up in the scandal and hopefully allow some level of closure for those who faced such injustice between 1999 and 2015.”