Watch live as Kemi Badenoch appears before the Post Office Horizon IT inquiry on Monday, 11 November.
The former business secretary and her successor, Labour's Jonathan Reynolds, are likely to be questioned on problems related to compensation for victims of the scandal.
More than 900 subpostmasters were prosecuted between 1999 and 2015 after faulty Horizon accounting software made it look as though money was missing from their shops.
Questions could also focus on the new Tory leader's row with ex-Post Office chair Henry Staunton.
William Paul Patterson, director of Fujitsu Services Limited, will also testify.
It comes after Sir Keir Starmer responded to campaigner Sir Alan Bates’s requests for help with settling redress claims for those affected by the scandal.
Sir Alan told MPs that the prime minister had not yet responded to his letter urging him to ask the Department for Business and Trade (DBT) to set a deadline of March next year for payments, but Downing Street confirmed hours later that a response had been sent.
Sir Alan was representing claimants from the 555 subpostmasters who took the Post Office to the High Court between 2017 and 2019 – also known as the GLO scheme.
He told MPs that 70 of the GLO scheme claimants have died while compensation is being sorted out, with others now “well into their 80s… that are still suffering”.
Number 10 declined to commit to the campaigner’s suggested payment deadline.
