Over the next four years Arcadis, Turner & Townsend and Gardiner & Theobold will provide access to a variety of commercial services, project and programme management resources for use on the project.

Martyn Court, Project Leader at Arcadis, said: “We have been working with Thames Water for the last four years, throughout the procurement phase and supporting the transfer of the project to its new owner last year.

“With a team of more than 30 people involved in the project – from Business Advisory and Risk and Cost specialists, through to Water Conveyancing and Tunnelling experts – it’s a real testament to the strength of our combined expertise to be assured of our continued involvement.”

Peter Depledge, Director of Infrastructure for Turner & Townsend, said: “We’re delighted to be playing a role in ensuring the timely delivery of such a huge and important project which will deliver a positive outcome for Londoners for generations ahead.”

G&T Partner, Rob Knight, said: “Having had an involvement in the Thames Tideway Tunnel Programme since 2013, Gardiner & Theobald is delighted to have been appointed as a key supplier to the Commercial Support Services Framework.

“We are looking forward to working with the Tideway team and providing our skills and experience on this major London project.”

Mark Sneesby, Chief Operating Officer at Tideway said: “As we start main construction work on the Thames Tideway Tunnel, we are confident that having the knowledge and expertise of three of the most prominent consultancies will be a huge asset in our work to clean up London’s river.”

The Thames Tideway Tunnel is a 25km sewer tunnel that will help tackle the tens of millions of tonnes of raw sewage that pour into the River Thames each year.