TClarke is understood to have withdrawn from the mechanical and electrical delivery team on the £4bn Agratas electric vehicle battery gigafactory in Somerset.

Industry sources said the building services specialist has stepped away from the Gravity Smart Campus project near Bridgwater following mounting “relationship problems” with client Agratas, the Tata Group’s global battery business.

The move will see TClarke redeploy staff previously assigned to the project across other parts of the business.

TClarke and NG Bailey were appointed around 18 months ago as joint MEP delivery partners on the huge battery plant scheme.

NG Bailey is now expected to take on the bulk of TClarke’s package, with a specialist contractor likely to be drafted in to deliver the complex cleanroom installation works needed for battery production.

One insider said: “The relationship between Agratas and TClarke has been increasingly strained in recent months as the project advances towards the start of installation works.

“It seems that has now resulted in TClarke and Agratas parting company.”

Sir Robert McAlpine remains construction manager on the delayed project, although its role has evolved towards a more project management-style function as Agratas deals directly with a number of main package contractors.

The change comes just weeks after a major MEP supply chain “meet the buyer” event linked to the project and will now increase pressure on NG Bailey to mobilise additional staff for the massive installation programme.

The scheme is running many months behind schedule although the pace of work is ramping up.

Steelwork contractor Severfield recently completed the structural frame for the first phase of the gigafactory, clearing the way for cladding installation before major MEP works begin.

Agratas is also pressing ahead with enabling infrastructure around the site.

Earlier this year Costain secured a £123m contract to design and build a new motorway junction on the M5 to serve the battery plant.

The five-year project, known as Junction 22A, is intended to ease pressure on the motorway network as the Somerset site ramps up construction and future operations.

Market engagement is also underway for procurement of a Water Supply and Wastewater Infrastructure Provider.

When complete, the Gravity Smart Campus will become the UK’s largest electric vehicle battery manufacturing facility.

TClarke would not comment on the situation.