One irate training specialist warned the system is “on the brink of collapse” as problems continue to plague skills card renewals.

Companies are also threatening legal action over loss of earnings as plant operators struggle to secure the cards they need to operate on site.

CPCS was sold to awarding organisation NOCN Group by the Construction Industry Training Board last year.

Problems have been ongoing since late last year when NOCN transitioned over the renewal test booking system.

The Enquirer has been deluged with complaints about the new system from all sides of the industry.

NOCN has been battling to fix glitches and catch-up with a huge backlog of cards to be issued.

But one operator said: “I can’t seen any improvement. I tried to speak to the call centre last week and was on hold for more than an hour.”

A training specialist added: “We’ve still got a raft of red and blue card applications which went in in November and have still not been received.

“It’s an absolute shambles and is costing companies a fortune in terms of lost work and delays.

“My clients are now asking who they should go after for loss of business and earnings.”