All major parties face questions about why it took an ITV drama to provoke meaningful political action on the Horizon scandal.

Campaigners have spent decades seeking justice for wronged post office operators, including at least 700 people who were prosecuted by the Post Office and other bodies between 1999 and 2015 based on the botched Horizon IT system.

But progress towards addressing one of Britain’s worst miscarriages of justice and providing compensation has been painfully slow.

“All three political parties had a role to play,” one former postal affairs minister, the Conservative MP Paul Scully, said this week. We look at the role played by the three main parties.

The Conservatives

The scandal has grown under the watch of five Conservative prime ministers, with the party being in power since 2010.

Rishi Sunak faces questions about why his government has only addressed the scandal with urgency since the broadcast of ITV’s Mr Bates vs The Post Office.

It was Boris Johnson, then prime minister, who had committed in February 2020 to “getting to the bottom of the matter” through an independent inquiry, which was established in non-statutory form later that year. But its progress has been repeatedly halted by obstacles, many of them put in place by the Post Office itself.

Amid a public outcry, Sunak announced this week that emergency laws would “swiftly exonerate and compensate victims”.

A focus is also now falling on the Conservatives’ links to Fujitsu, which provided the faulty Horizon accounting software on which the convictions were based. Simon Blagden, a Tory donor who chairs the government’s Building Digital UK agency, was described by Fujitsu UK in 2015 as a member of its leadership team who sat on its UK and Ireland responsible business board, as well as being chair of one of its subsidiaries, Fujitsu Telecommunications, from 2004 to 2019.

However, the Tory peer and former MP James Arbuthnot has been one of the most trusted and persistent voices throughout the scandal.

The Liberal Democrats

The Liberal Democrats’ leader, Ed Davey, has faced heavy criticism for letting down victims of the scandal when he was postal affairs minister between 2010 and 2012.

Davey had initially refused to meet Alan Bates – the campaigner featured in the ITV drama – when he was a minister, turning down a request in 2010 with the claim: “I don’t believe a meeting would serve any useful purpose.” They met later that year.

Under intense pressure, Davey has declined to apologise, instead accusing senior Post Office managers of unleashing a “conspiracy of lies” against successive ministers. The party has gone on the offensive, with MPs being given a standard letter to send to constituents asking about Davey’s role, and have called for Ofcom to investigate GB News over alleged impartiality breaches in its coverage.

There has been a mixed picture when it comes to the other Liberal Democrats who had a role to play. Bates has said that he warmed to Norman Lamb, who succeeded Davey as postal affairs minister, and appeared “quite concerned”. But while Lamb agreed to meet the Justice for Subpostmasters Alliance (JFSA), the MP’s tenure in the role was less than a year.

Jo Swinson took over from Lamb during a period when an external review of the Horizon IT system was being carried out by the forensic accountants Second Sight, brought in by the Post Office as pressure mounted.

But in a statement to the House of Commons, Swinson backed up the position of the Post Office that there was “absolutely no evidence of any systemic issues with the computer system”. She has subsequently said that she had been misled.

Labour

It was under a Labour government, that of Tony Blair, that the Horizon system was introduced to replace the old paper-based tills that had been used in post offices across Britain.

But, while the party was not in power when concerns started being widely expressed, a focus for the ongoing inquiry will be whether Labour ministers were intent on pressing ahead with the system despite initial reservations.

Harriet Harman, then secretary of state for work and pensions, had written as far back as 1998 to Blair to warn him there was a risk that the project would fail to achieve its objectives, while the then prime minister also received a Treasury briefing the following year outlining a series of failures.

Ian McCartney, who was handed ministerial responsibility for the Post Office in the first weekend of Blair’s premiership, told the inquiry in September last year that he had discussed a major problem regarding the project with the then minister of welfare reform, Frank Field, who said he was “appalled” by a lack of documentation.

But McCartney told the inquiry: “To have abandoned the Horizon project would have been calamitous. There would have been no contract, so we would have had to start from the beginning again.”

The current Labour leadership’s exposure to the scandal centres on the fact that Keir Starmer was heading the Crown Prosecution Service during a period it was also taking actions against somepost office operators.

Starmer, who was director of public prosecutions between 2008 and 2013, denied he was aware of those prosecutions.