The National Infrastructure and Service Transformation Authority (NISTA) has given an update on the country’s largest and most complex  infrastructure projects.

The Government Major Projects Portfolio (GMPP) comprises the most complex and high-value projects and programmes.

The Major Projects Annual Report 2025 to 2026  shows most projects were rated green or amber, showing that delivery is likely or feasible for the majority. Red-rated projects, some of the most ambitious and complex programmes, are receiving “deeper, more targeted support” to help get them back on track.

During the review period, 42 projects left the GMPP, with 26 of those having delivered against their objectives, including the Biosecurity, Borders and Trade Programme (by DEFRA), Digitising Social Care (by DHSC) and Drug Testing Services (by the MOJ).

A further eight left the GMPP as they no longer met GMPP reporting criteria, one was replaced by successor projects  and seven were brought to early closure. Of the projects that left the portfolio, 17 have  a green rating and 21 with an amber rating.

Since the previous annual report published in August 2025, 18 projects have improved from an amber to a green rating, while one project has improved from red directly to green.

Becky Wood, chief executive of NISTA, said: “Delivering some of the Government’s most ambitious and complex programmes is never easy, so it is expected that projects will face different challenges and perform differently at various stages of delivery.

“These assessments should not be seen as a definitive judgement on whether a project will ultimately succeed or fail. Instead, they provide an early warning, helping us identify risks sooner, understand where pressures are emerging, and work with departments to address issues before they become more serious.

“By making better use of performance data, strengthening independent assurance, and providing access to expert advice, NISTA can help ensure that project teams receive the right support at the right time – improving the likelihood that major government programmes are delivered successfully for the public.”

The report shows that, at the end of March 2026: 29 projects (15% of the GMPP) were rated green; 109 projects (58%) were rated amber and 34 projects (18%) were rated red; with 17 projects (9%) exempt from any rating.

For the first time, NISTA’s reporting includes the new ‘mega project’ classification for the most complex and strategically significant programmes which typically have a whole-life cost exceeding £10bn and span multiple parliaments. Three projects were initially granted mega project status: Sizewell C, HS2 and Dreadnought.

Click here to read the full report.