Dozens of sub-postmasters with criminal convictions linked to a computer scandal won an important round in their legal battle to clear their names on friday, after the uks post office said it would not contest their appeals.

The state-owned organisation will not fight 44 out of 47 cases due to go before the criminal court of appeal, a move which lawyers said made it more likely that the convictions for offences such as theft, fraud and false accounting will be quashed.

If they are quashed, it could pave the way for the sub-postmasters to sue the post office for malicious prosecution. at least 100m in taxpayer money has already been spent on legal bills and the settlement of a related lawsuit last year.

Following the decision not to contest the cases, post office chairman tim parker issued a personal apology on behalf of the company for its historical failings.

Post office is resetting its relationship with postmasters with reforms that prevent such past events ever happening again, he said.

The decision is a significant milestone in a campaign waged over many years by the sub-postmasters, who say they were wrongly accused because of a faulty it system that led to financial shortfalls in their branch accounts.

Lives were ruined and people forced into repaying supposedly missing money, sometimes up to tens of thousands of pounds. others were made bankrupt or even served prison sentences, in what has been described as one of the worst miscarriages of justice in recent uk legal history.

A high court judge last year concluded that the horizon software, used in post office branches, contained bugs, errors and defects that caused discrepancies in accounts.

Neil hudgell, a solicitor representing 34 former sub-postmasters, said while the criminal court of appeal could theoretically order retrials of the 44 cases that are not being contested, he thought the post office was unlikely to request this.

This is a landmark moment, he added. some people have lost their homes, businesses and reputations. some are on medication for the emotional trauma they have suffered, so whilst this may never repair all the damage that has happened, this will help provide redress.

Among the convictions that could now be overturned was one handed down to karen wilsons late husband julian, who ran a post office in worcestershire.

He was sentenced to 300 hours of community service in 2009 after being advised to plead guilty to a false accounting charge and forced to make good a 27,000 shortfall and pay legal costs.

Its not about the money, its about the injustice, said ms wilson. i feel like my heart can beat at a normal pace and my head is a little calmer. i feel so relieved for him.

The development comes after the criminal cases review commission referred the 47 cases, which were brought as private prosecutions by the post office, to the criminal court of has potential implications for hundreds of other people who were pursued in a similar way by the post office following the introduction of the horizon computer system in 1999.

The post office itself is looking into 900 prosecutions, and this week the government appointed a former judge to lead an inquiry into the scandal.