Question to the Cabinet Office:

To ask Her Majesty's Government on what criteria the Infrastructure and Project Authority concluded that the Thames Tideway Tunnel no longer requires its oversight and reporting.

The Thames Tideway Tunnel is not a Government project and would therefore not normally be subject to IPA oversight and monitoring. However, given the scale and nature of the project, it was decided that IPA would provide oversight and assurance for the set-up of the project.

The IPA confirmed that the conditions were right to return the project to DEFRA assurance through a Project Assessment Review in May 2016 and formally returned responsibility in 2017. This was only done once IPA were content that DEFRA had strong and appropriate assurance in place to ensure HMG’s interests were protected, and was documented through an exchange of letters between the CEO of the IPA and the DEFRA Accounting Officer.

Although no longer on the Government major projects portfolio, DEFRA and IPA continue to work closely together on the project.