The Enquirer understands that Graham Lill left the project last month.

Sir Robert McAlpine has been overseeing site preparation work for Tata-owned Agratas since last summer but the job has faced construction delays as plans for the site are scaled back.

Steelwork for the first phase was due to start in January but it is understood Severfield has now signed the contract and will start on site this summer.

Client Agratas has confirmed that the size of the first 2.6m sq ft building is being reduced by “about 100 metres.” and the “timeline is shifting slightly” with the first phase now due to be completed in 2027 rather than 2026.

A site source said: “It’s a big deal for a project director to depart a job of this size.”

Sir Robert McAlpine declined to comment.