The collapse comes just five weeks after management at Hydrock separated out the remediation business, rebranding what was then Hydrock Contracting as QDS Contracting.

Hydrock said the move followed a strategic review of its business which concluded that the loss-making remediation arm could no longer be supported.

The business was formed when Hydrock Contracting bought rival contractor QDS for £450,000 back in April 2013. But latest published results show that the combined firm was struggling with balancing risk and was burdened with legacy contracts.

2017 accounts for Hydrock Contracting show it lost £2.5m from a revenue of £24m.

The firm’s biggest job was for EDF at Hinkley Point C where it completed a £40m site remediation package.

Announcing this decision, Dr Brian McConnell, Hydrock group managing director, said that going forward, Hydrock would focus solely on its core business of multi-disciplinary engineering design and consultancy.

He said: “It is with great sadness and reluctance that as a board of directors we have had to take this decision.

“Remediation contracting work is increasingly high risk and low margin due to the number of organisations expanding their reach into what had traditionally been a very specialist and technical sector.

“This situation has resulted in work packages proving to be commercially unsustainable in the long term. Coupled with some challenging, legacy projects, this has led to our decision to place QDS Contracting Limited into administration.”

He added: “By contrast, Hydrock’s core business of multi-disciplinary engineering design and consultancy is well-established and successful, delivering for blue-chip clients, leading architects, developers and contractors across the UK.

“This business has grown markedly over the last three years to become the most significant part of the group in terms of turn-over, profit and staff numbers, with over 400 staff employed in our consultancy business.

“We’re regularly out-performing the competition to offer clients an outstanding multi-disciplinary design approach that unlocks complex sites, creates value from property assets, and secures planning permission for future development.”