New GMPP offers more targeted support from the centre of government for the most nationally significant, highest-impact projects and programmes
Significant reforms to the Government Major Projects Portfolio (GMPP), announced today, will ensure more targeted support from the centre of government for the most nationally significant and highest‑impact UK projects and programmes.
The reforms will better drive departmental accountability and improve value for money for taxpayers through focused support in priority areas, resulting in better delivery of our vital infrastructure and public services underpinning the government’s growth agenda.
In recent years, the GMPP – previously managed through the Infrastructure and Projects Authority and now managed and overseen by NISTA - has expanded significantly, reflecting the growing number of large and complex projects delivered across government.
To ensure central oversight remains proportionate and targeted, government is refocusing central support. From 1 April 2026, the size of the GMPP will be reduced from over 200 projects to around 80.
A smaller, more focused GMPP will allow NISTA to target expert advice and assurance where it adds most value, strengthening confidence in the delivery of benefits from government investments.
Departments and delivery bodies will continue to lead their projects as directed by their ministers, reflecting the function’s deep knowledge of their policy areas and systems. This gives leaders who are working most closely with the project clear ownership of decisions, outcomes and accountability for delivery.
NISTA will continue to provide broader support through tools and guidance, deepening its data capabilities and its offer to departments. It will also develop its role earlier in a project, ensuring they are better set up from the outset.
These changes form part of a wider reform programme to speed up delivery, target specialist expertise where it is needed the most, and strengthen departmental decision‑making.
In exceptional circumstances, government may add projects or programmes to the GMPP where they are of particular strategic importance - such as those that are very high risk or underpin critical national infrastructure - and where NISTA’s support is expected to improve delivery confidence.
Government has also set out for the first time a clear definition of “mega projects”. These are programmes with transformational impacts on the economy, society or national security, with whole-life costs above £10 billion, which typically will take more than 10 years to deliver.
For too long, projects have been run through overly complex systems that slow decisions down and blur accountability.
Refocusing the GMPP means we can direct specialist expertise to the most complex, high-risk and strategically relevant projects – so that we deliver faster, improve value for money, and strengthen public services in ways people will feel.
Our Plan for Growth is about building a stronger UK - unlocking investment and opportunity across every nation and region and delivering modern infrastructure and better public services.
Delivering the government’s priorities is underpinned by strong delivery right across the project system. These reforms simplify oversight, sharpen responsibility in departments, and focus expert support where it will have the greatest impact.
Refocussing our GMPP means that NISTA can provide more targeted and agile support as national priorities evolve and risks change. We will also be working more closely with those projects at the earliest stages that are likely to be nationally critical, ensuring projects can be set up to succeed from the outset.
We continue to support departments with clear standards, practical tools, high‑quality training and shared learning - ensuring teams across government have what they need to deliver successfully.
Project delivery professionals will continue to lead and deliver their projects and programmes, drawing on their expertise and professional judgement.
NISTA remains committed to strengthening the Government Project Delivery Function across the whole system by deepening capability - providing expert advice, targeted training for Senior Responsible Owners, and practical tools and guidance for wider professionals.
It will also work closely with departments to better understand how non‑executive roles and the boards of the arm’s‑length bodies that are essential partners in delivering the nation’s infrastructure - particularly across the regulated sectors of energy, water, transport, and housing – can support accountable officers and the overall assurance approach to delivery.
NISTA is also deepening its own capability and what we can offer to projects across the GMPP and beyond, ensuring we harness the data we gather to share insights, better predict challenges in advance, and share lessons in real time through improvements in data, analysis and insights.
Government investment and commitment to major projects remains a priority, supporting delivery of vital infrastructure and public services and driving economic growth across the UK.