Treasury ministers appear to have broken government guidelines by failing to publish details of their department’s spending for several months, and in some cases more than two years. Public records show the Treasury is the worst department in Whitehall for publishing key data on what its officials are spending public funds on, despite its role overseeing spending across government. The gaps add to concerns about high spending levels and low transparency at the Treasury, including during the period for which Rishi Sunak was chancellor. Earlier this year it emerged Sunak’s Treasury had spent £3,000 on photographs to hang on the department’s walls and £4,500 on rooms in Venice for a G20 meeting. Fleur Anderson, the shadow paymaster general, has written to John Glen, the chief secretary to the Treasury, to ask why the department has failed to publish its spending data for so long. In her letter, she said: “The Treasury’s task is sorely undermined when it cannot get its own house in order, and instead stands exposed as the worst-performing department when it comes to reporting the details of its own spending.” A Treasury spokesperson said: “Internal staffing changes have led to a delay in publication. We’re committed to transparency and will publish all required data in due course.” Under government guidelines put in place by the coalition and Conservative governments, ministers are meant to publish details of large parts of departmental spending every month. They include anything for which the department paid more than £25,000, anything for which officials paid more than £500 on a government spending card and any staffing and consultant costs. David Cameron was the first to force departments to publish details of spending over £25,000, writing to departmental chiefs weeks after taking office to warn them to adhere to the new rules. Since then, however, departments have become increasingly lax about sticking to those guidelines. The Treasury has not published what its officials have spent on government cards since December 2021. The last month for which it published large item spending was January 2022. Its latest published staffing data comes from March 2022. The lack of data makes the Treasury by far the least transparent department in Whitehall. All others have provided spending information for at least some of 2022, and many for the entire year. They include the Department for Business, Energy and Industrial Strategy and the Department for International Trade, both of which have ceased to exist after the prime minister’s most recent reshuffle. Anderson said: “It is an absolute farce that two departments which no longer exist are managing to keep their transparency publications more up to date than the Treasury.”