Connaught bosses are currently struggling to keep the firm out of the bank’s hands after it ran out of funds to pay suppliers as debts soared above £200m.

Rok issued another profit warning yesterday and suspended its Finance Director as problems intensified at its plumbing, heating and electrical division.

Connaught blamed a slowdown in spending on social housing maintenance for its troubles while Rok said it had suffered through “serious failings” in financial controls.

But rival contractors have accused both firms of winning work through ultra-low bids.

One contractor told the Enquirer: “This is a case of chickens coming home to roost for both of these firms.

“It’s no real surprise to most people in the industry because they have been winning work with suicidally low bids to impress the city with their order books for years.

“The main problem for them is that clients have got a lot more savvy and the old days of putting in a low bid then working up the price once you have started are long gone.

“There is hardly any wriggle room in these contracts so the price you bid is the price you get.

“I can see Connaught having to give up contracts but replacement firms won’t work for the same rates they quoted at because the numbers just don’t stack-up.”

A Rok spokesperson said: “The statement Rok issued to the City yesterday advising that its profits for the year would not be a high as previously hoped gave a clear account of the reasons behind the announcement.

“It also stated that trading within the Construction and Social Housing businesses was strong and that these divisions, with good order books, were positioned to perform well during the remainder of the year.

“At no time has it ever been suggested by any reliable source that Rok puts in prices for its services that are unrealistically low.”