The Justice For Subpostmasters Alliance (JFSA) says that more than 300 current and former subpostmasters have joined the joint legal action against Post Office Ltd since March, taking the total number of applicants to more than 1,300.

The claimants allege they suffered at the hands of Post Office Ltd through “a campaign of withholding information, bullying and intimidation”. The legal action – in the form of a Group Litigation Order (GLO) – will focus on Post Office Ltd’s treatment of subpostmasters, managers, agents and employees in relation to problems associated with its Horizon system.

Since 1999, when Post Office Ltd rolled out its Horizon system, hundreds of subpostmasters have experienced “unexplained” shortfalls in their financial accounts. Post Office Ltd is alleged to have pressurised subpostmasters to make good the shortfalls with their own money and in some cases admit to false accounting or other criminal activity. The shortfalls, in some cases, run into tens of thousands of pounds.

JFSA says that, according to information supplied by applicants to the joint action, 85% have been pursued for money by Post Office Ltd in relation to alleged shortfalls, while over 85% of claimants believe they have suffered ill health or reputational damage as a result of Post Office Ltd’s behavior. As many as 69% of those who resigned said they felt pressured to do so by Post Office Ltd or its agents.

The legal action was approved by the High Court earlier this year. Post Office Ltd is defending the claim.

Alan Bates of the JFSA said: “The treatment of these men and women by Post Office Ltd is a national disgrace. Hundreds of dedicated subpostmasters have suffered, and continue to suffer, at the hands of these corporate bullies in order, we believe, to cover up flaws and errors within Post Office Ltd’s Horizon system. These problems, compounded by a blame culture in which postmasters were bullied and scapegoated, have cost our people their savings, their jobs, their livelihoods, their health, their reputations and in some cases their freedom.

“Our evidence will show how subpostmasters were kept in the dark by Post Office Ltd about the scale and frequency of the problems and were made to feel like isolated cases.

Acting together we have the chance to take on this injustice and hold Post Office Ltd to account for its actions.”

Post Office Ltd welcomed the original High Court ruling, saying: ”The Post Office welcomes the Group Litigation Order as offering the best opportunity for the matters in dispute to be heard and resolved. We welcome the progress that has been made, but will not otherwise comment on litigation whilst it is ongoing. We continue to have confidence in the robustness of the Horizon system which has around 78,000 users across 11,600 branches nationwide to process six million transactions a day.”

Any subpostmaster who was in position after 1999 and experienced issues with Post Office Ltd and its Horizon system, including alleged shortfalls or discrepancies, may be eligible to join the case, said JFSA. Contact can be made either through the website, by email or by telephone on 0800 304 7727.

The deadline for applications to join the legal action is 26 July 2017.