A postmistress has threatened to stand against Ed Davey in his constituency at the next election, amid mounting fury over the Liberal Democrat leaders' role in the scandal.
Yvonne Tracey, a local independent councillor, was previously the deputy manager of a local Post Office branch.
Residents in the seat are weighing up standing Tracey against Davey in the next election.
The MP is facing growing pressure over the scandal, after being accused of having turned down a meeting with campaigner and former sub-postmaster Alan Bates while he fought for justice for postal workers.
A postmistress has threatened to stand against Ed Davey in his constituency at the next election
PA
But the Lib Dem leader has attempted to distance himself from the scandal, claiming he was "deeply misled" about the situation during his time as post office minister.
Davey, who is now the leader of the Liberal Democrats, served as Minister for the Post Office between 2010 and 2012 in the coalition government.
More than 700 sub-postmasters were handed criminal convictions between 1999 and 2015 after faulty software wrongly suggested the employees were stealing money.
It has since emerged that Davey, along with several other ministers, faced repeated warnings about the accounting problems and issues with the software.
A spokesperson for the Lib Dem politician said he "bitterly regrets” that the Post Office was not honest with him.
They added that "in hindsight", Davey wishes that he could have done more.
Ex-postmistress Sally Stringer called for a "concerted effort to get the responsible individuals", claiming that the root of the scandal “goes back to ministerial decisions” - some of which she described as being “wicked”.
Giving evidence to the ongoing public inquiry, Stringer said: "There has to be a concerted effort to get the responsible individuals.
"It needs to be done as a block, otherwise those responsible will walk away nicely. I would like Vince Cable and Edward Davey to be cross examined about what they knew and did.”
She added: " I think the problems with Post Office Limited goes back to ministerial decisions taken during the coalition government of the Liberal Democrats and the Conservatives formed in 2010.
"The ministerial decisions range from incompetent to wicked."
Yesterday, Prime Minister Rishi Sunak confirmed the Government will introduce new primary legislation to exonerate those convicted as a result of the Horizon IT software.
The legislation will also see compensation handed to the victims of the scandal.
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Sunak told MPs at PMQS: "Today I can announce that we will introduce new primary legislation to make sure that those convicted as a result of the Horizon scandal are swiftly exonerated and compensated.
“We will also introduce a new up-front payment of £75,000 for the vital GLO (group litigation order) group of postmasters.”
He described the scandal as "one of the greatest miscarriages of justice in our nation’s history".
The PM added: “People who worked hard to serve their communities had their lives and their reputations destroyed through absolutely no fault of their own. The victims must get justice and compensation.”