The Cabinet Office spent more than £30,000 trying to block the publication of a questionnaire used by ministers to declare their financial interests.
BBC News first requested a copy of the document in January 2023 using Freedom of Information laws after the then Conservative Party chairman Nadhim Zahawi was sacked for breaching the ministerial code.
The Independent Adviser on Ministers’ Interests said Zahawi had failed to declare that he was the subject of an ongoing investigation into his taxes when he was appointed chancellor in July 2022.
This was despite the ministerial declaration of interests form he was asked to complete including specific prompts on tax affairs and HM Revenue and Customs. investigations and disputes.
Rishi Sunak’s administration refused to release the document to the BBC saying ministers needed to have confidence that the process was confidential.
But in September 2023 the Information Commissioner’s Office (ICO) ruled it should be disclosed in the public interest.
The Cabinet Office then appealed to the Information Rights Tribunal, which in February this year upheld the ICO’s findings.
The government’s decision to pursue the case against its information watchdog cost the taxpayer a total of £32,251 in legal costs.
Rose Whiffen, senior research officer with the campaigning charity Transparency International UK, said: “The publication of ministers’ interests is a key accountability tool, allowing the public to identify how policy decisions may be influenced by private interests.
“Transparency shouldn’t end with published declarations. Government should embrace transparency as the default, not fight expensive legal battles to maintain unnecessary secrecy.”
The form, which you can read here, reveals that when Nadhim Zahawi was appointed chancellor in July 2022, he was asked: “Are your tax affairs up to date?” and “Are you, or have you ever been in despite with, or under investigation by, HM Revenue and Customs?”.
Zahawi, along with other ministers, was also asked if any of his financial arrangements could be “perceived” as tax avoidance schemes.
The former chancellor is since understood to have paid a substantial penalty to HMRC and has said his tax error was “careless and not deliberate”.
Some of the other questions included on the form are a reminder of controversies that have plagued previous administrations.
In a section in which ministers are asked to declare what property they own, the form reminds them: “Your main second home for parliamentary purposes should be the same for all other purposes, including capital gains and council tax”.
During the expenses scandal, which emerged in 2009, some MPs were revealed to have changed what they declared as their primary residence when selling property to avoid paying tax.
The version of the form which the BBC has seen dates back to July 2022 when the Conservative Party were still in power.
The Cabinet Office has subsequently refused a separate BBC News request to see the form currently in use.
A government spokesperson said: “The government is fully committed to transparency.
“We proactively publish more information outside the Freedom of Information Act than ever before, amounting to thousands of documents each year.”