The UK Health Security Agency has issued a preliminary market engagement notice for the vast design and build package, marking the clearest sign yet that the delayed flagship project is back on track after years of uncertainty over costs and value for money.

Before committing to procurement, agency chiefs want to test the contracting market to help them decide whether the huge public health security research campus should be delivered under a single mega design and build contract or split into multiple packages to improve competition, deliverability and value for money.

The works package covers a new science and headquarters building, medium containment laboratories, offices, logistics and support facilities, an energy centre, education buildings and campus-wide infrastructure on the 40-acre Essex site.

Work is expected to run from January 2028 until September 2038, with an option to extend to 2042, as UKHSA targets full campus operational readiness by 2038.

The latest procurement follows a lengthy review that effectively froze the programme.

Since 2022, UKHSA suspended its main construction supply chain while HM Treasury and the Department of Health and Social Care repeatedly reassessed whether Harlow remained the best value for money option after costs rose well beyond the project’s original £2bn estimate.

Despite the delays, ministers have now backed the scheme, which will create Europe’s largest national health security and biosecurity campus by bringing together UKHSA’s scientific operations from Porton Down, Colindale and its London headquarters onto a single site.

The new procurement excludes the highly specialised National Biosecurity Centre containing the UK’s Category 4 containment laboratories, which will be delivered under a separate contest because of its complex security and technical requirements.

Instead, the successful contractor will deliver accommodation for around 2,400 staff, Containment Level 2 and 3 laboratories, headquarters offices, logistics hubs, security and reception facilities, education buildings, and an energy centre.

Work also includes utilities, roads, parking and extensive external works, while coordinating with the separate high containment laboratory project.

An industry engagement day will be held in Harlow on 10 September, with contractors invited to help shape procurement, commercial arrangements, risk allocation and programme sequencing ahead of a formal tender expected in November.

The revival comes after earlier enabling contracts were awarded before the programme stalled.

Kier secured the specialist bioscience laboratory building package, while Wates was appointed for the arrivals, administration and logistics buildings and refurbishment works. VolkerFitzpatrick landed the infrastructure, external works and energy centre package before the project was paused for review after demolition works.

To express an interest in attending the engagement day click here. A formal invitation to tender is expected to be published at the end of November.