Hundreds of subpostmasters were wrongly accused of stealing from branches because of the faulty IT software.
Seema Misra from West Byfleet was sent to jail in 2010 when she was 8 weeks pregnant and gave birth while on a tag.
A newsletter by Sir Alan Bates, the leading man behind the campaign, states that “if nothing has greatly improved” then a “specialist law firm” will be called in.