Recently retired Conservative MP James Arbuthnot will continue to fight for subpostmasters that allege injustice at the hands of a Post Office IT system, as he takes his seat in the

House of Lords.

Arbuthnot, who joined the house of Lords this week as Lord Arbuthnot of Edrom, has been the voice of a group of 140 MPs campaigning for subpostmasters that have been fined – and even sent to prison – for offences they claim they have not committed.

Post Offices use an IT system developed by ICL/Fujitsu Services, called Horizon, for their accounts. Computer Weekly first revealed the stories of subpostmasters who had received heavy fines and even jail terms for alleged false accounting – which they blamed on the Horizon accounting system – in 2009.

The Post Office denies system-wide problems with Horizon.

Arbuthnot told Computer Weekly he will “most definitely” continue to seek justice for subpostmasters that believe they have suffered at the hands of a faulty Post Office IT system. “I’ve told the responsible minister, the chief whip and the leader of the house,” he said.

In March 2015, following news of his retirement as an MP after 28 years, he said he remained determined to get to the bottom of the problems associated with Horizon.

Alan Bates, a member of the Justice for Sub-postmasters Alliance (JFSA) pressure group, which was set up to campaign for the subpostmasters affected, said Arbuthnot had been a good supporter of the campaign.

“It is excellent news that he will continue to support the campaign,” said Bates.

The Criminal Courts Review Commission (CCRC) is reviewing subpostmasters’ claims of wrongful prosecution.

Read Computer Weekly timeline of events