HM Treasury concluded its review of the Green Book in June 2025. Since then, it has published a clearer, shorter Green Book, ensuring decisions are no longer based solely on single metrics such as benefit-cost ratios (BCRs), but instead consider the full range of potential impacts.

HM Treasury has streamlined business case guidance, and has published the findings of an independent review into the Green Book discount rate, ensuring the government is taking a fair view of long-term investment proposals.

HM Treasury is also piloting place-based business cases (PBBCs) with four early adopter locations, working in close partnership with regional, local and devolved governments, including mayors, to test a new approach to appraisal that puts local objectives at the centre. Business cases for major projects and programmes are being published consistently, meaning the public can have confidence that every pound of taxpayers’ money is being spent on projects that deliver the best possible value.

HM Treasury has published a report on its progress in implementing the conclusions of the Green Book Review in 2025. The report can be found here: https://www.gov.uk/government/publications/green-book-review-2025-one-year-on

The Pension Schemes Bill was introduced on 5 June, implementing the reforms outlined in the Pensions Investment Review.

The Bill sets out a vision for a pensions market with fewer, larger schemes which can use the benefits of scale to invest in a wider range of productive assets as well as deliver better outcomes for savers.

These reforms support the Mansion House Accord, an industry-led pledge to invest at least 10 per cent of defined contribution default funds into private markets by 2030, of which at least half is in the UK.

Furthermore, last year the British Business Bank announced the establishment of the British Growth Partnership, designed to crowd in investment from UK pension funds for our most innovative, fastest growing companies.

HM Revenue and Customs (HMRC) estimates the size of the tax gap, which is the difference between the amount of tax that should, in theory, be paid to HMRC, and what is actually paid. The tax gap statistics are published annually, most recently on 19 June 2025, with the next release planned for June 2026. [1]

The latest estimate of the wealthy customer group tax gap was £2.1 billion for the tax year 2023 to 2024. [2]

[1] The latest estimates include tax years from 2005 to 2006 through to 2023 to 2024 and are available at: https://www.gov.uk/government/statistics/measuring-tax-gaps.

[2] Historical estimates for the tax gap for wealthy customers can be found in table 1.4 here: https://www.gov.uk/government/statistics/measuring-tax-gaps-tables

My Lords, the tax gap is estimated to be 5.3% of total theoretical tax liabilities. At the Budget last year, the Chancellor announced the most ambitious package ever to close the tax gap. The Government then built on this at the Spring Statement, setting out plans to make it easier for taxpayers to pay the right amount of tax for a modern and digital tax system. These measures will raise an additional £7.5 billion of tax revenue each year by the end of the Parliament.

The Government is committed to ensuring that the tax system provides the economic stability needed for growth.

At the Budget in October the Government honoured the manifesto commitment to cap Corporation Tax and outlined a clear plan in the Corporate Tax roadmap. The Government also took steps to repair the public finances through reforms that removed inefficient and distortive reliefs from the tax system. This included removing loopholes to ensure the tax system was more sustainable alongside delivering on the Government’s manifesto commitments to raise revenue in a fair way.

At Spring Statement 2025 we went further and faster to close the tax gap, making sure that everyone pays the tax they owe, and in April the Government announced measures to simplify the tax system to help deliver the Plan for Change. These measures will reduce burdens on employers and small businesses, and reform the tax system to ensure it continues to be fit for the modern world.

The first part of the landmark Pensions Review has concluded with the publication of the Final Report of the Pensions Investment Review on 29 May 2025.

The ambitious reforms outlined in the Final Report will drive scale and consolidation in both the multi-employer defined contribution pensions market and the Local Government Pension Scheme in England and Wales. They will unlock billions of pounds in investment for productive assets, improve efficiency, and deliver better returns for savers. Estimates suggest the measures could increase a Defined Contribution pot at retirement by £5,900 for an average earner who saves over their career.

To deliver these reforms, the Government has introduced the Pension Schemes Bill, providing the necessary legislative framework to implement these reforms, alongside wider pension reforms. The Bill received its first reading on 5 June 2025.

These measures will support the new more ambitious industry-led voluntary Mansion House Accord, announced on 13 May 2025. The Accord is a commitment from 17 of the UK’s largest defined contribution pension schemes to invest 10% of their default funds in private assets, with half of that earmarked for the UK, by 2030. This will unlock more productive investment and help support the diversification of savers’ pensions assets.