New rules requiring major projects to publish a business case within four months of being approved by the Treasury have come into effect.
As of 11 June 2025, all projects and programmes in the Government Major Projects Portfolio are required to publish a summary, full or programme business case within the four-month timeframe, chief secretary to the Treasury Darren Jones has announced.
The Treasury has published guidance to help departments meet the requirement.
Jones said he had asked the Treasury to write to accounting officers telling them to ensure that all relevant business cases are “properly deposited”.
The documents will be accessible to the public via GOV.UK or the relevant body’s website, he said, as well as being placed in the House of Commons Library.
“This commitment will allow departments to meet their obligations to parliament easily and promptly,” Jones said.
The step follows a commitment made at Autumn Budget 2024 to increase the transparency of investment decisions by publishing business cases for major projects and programmes.
The Green Book Review, published in June alongside the Spending Review, reaffirmed the commitment and said the government would monitor progress on publishing business cases “on an ongoing basis”.
The review also promised to “radically simplify and shorten” both the Green Book and its associated business-case guides, which it said had become “too long and complex”, and clarify how much detail is “proportionate for business cases of different levels of cost and complexity”.
In his statement, Jones said: “Greater transparency around investment decisions can support the evaluation of projects and programmes, inform subsequent analysis, and enable better allocation decisions over time. Sharing best practice also helps to build capability, which in turn leads to better outcomes for project delivery and the public.”