The biggest, HSE Building Services, was saved from the collapse of HSE Group in July, after the management completed a buyout to save up to 100 jobs.

At the time Mark Aldridge, managing director of the central London firm, said “The acquisition provided an injection of working capital which would allow the company to absorb the loss caused by the administration of HSE Group.”

Administrators from London based MacIntyre Hudson are now handling the administration.

A source told the Enquirer: “I can confirm HSE Building Services is in administration and to be honest we are all a bit shocked.”

“I’m not really sure what has caused it.”

Meanwhile, the Hampshire-based ductwork contractor WML has also collapsed

The firm built up a reputation in London working on hospital and office jobs, but also worked across the whole of southern England and turned over around £5m at its peak.

Contract values have ranged between £10,000 and £2.3m, with many having labour intensive fast track programme requirements.

The firm forms part of the Gould Group, which continues to trade normally.

Administrators at the Bristol office of Mazars were unavailable for comment.