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.

Projects rated red include HS2 - but the report said there is a focus on resetting the high speed rail project to establish a "credible, deliverable baseline while maintaining cost control, improving productivity and strengthening governance arrangements".

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.

Civils contractors have said that evidence of improving confidence across the government’s portfolio of major projects highlights the need to stay the course on the UK’s infrastructure ambitions.

Ben Goodwin , director of policy and public affairs at the Civil Engineering Contractors Association (CECA), said: “The progress identified by NISTA is welcome and demonstrates the value of stronger oversight and earlier intervention to get projects moving when they encounter hold-ups.

“At the same time, NISTA’s report underlines the scale of the delivery challenge. An amber rating means that successful delivery is feasible, but that significant issues remain to be addressed, while the number of red-rated schemes shows that work still needs to be done to address the substantial risks that remain across the portfolio.

“Better data and improved early-warning systems can help identify problems sooner, but they must be matched by swift and decisive action to turn planned projects into investable, deliverable opportunities.

“This will mean the Government needs to redouble its commitment to a credible and funded project pipeline, and leaves no stone unturned in ensuring schemes are delivered via procurement models that engage contractors early in the process and allocate risk fairly."

Click here to read the full NISTA report.