Sir Robert McAlpine has been overseeing site preparation work for Tata-owned Agratas since last summer.

But work has now stalled at the piling stage for the first of three planned main buildings with 16,800 piles now installed.

Agratas has also confirmed that the size of the first 2.6m sq ft building is being reduced by “about 100 metres.”

The firm said: “Since we first began developing our site in 2023, battery manufacturing technology has moved fast.

“To stay ahead, we’re making some updates to the first phase of our build.

“Through new cutting-edge innovations, we’re making our operations more compact and even more efficient. The length of our first building will be shortened (by about 100 metres), meaning we can do more with less, cutting waste and boosting productivity without compromising on our ambition.”

Scaling back the designs has caused delays in the construction schedule and Agratas said its “timeline is shifting slightly” with the first phase now due to be completed in 2027 rather than 2026.

Steelwork for the first phase was due to start in January and Severfield yesterday confirmed that delays to a major project had contributed towards its latest profit warning.

Agratas said steelwork would now start on the site this summer.

One project source said: “The delays have seen some staff leave the job and it’s not a happy place to work at the moment.”

Once all phases of construction are complete, the facility is set to be the biggest of its kind in the UK and by the early 2030s will contribute almost half of the projected battery manufacturing capacity required for the UK automotive sector.