Amey, which presently operates in the region, lost the term maintenance contract to Scotland Transerv, which is due to take over responsibility for the routes next April.

A spokeswoman for Transport Scotland said: “We can confirm a bidder put in a price that was relatively low. The bid was thoroughly investigated and found to be abnormally low, carrying unacceptable risk. Therefore a decision was made to reject this bid.

“We will robustly defend any legal challenge that is brought forward but are unable to comment further at this time.”

One source told the paper: “Amey are adamant that they have priced perfectly correctly within the terms of what was allowed under the contract process. Apparently glaring errors were discovered in it and highlighted by Amey.”

Amey was not available for comment.

The new-style trunk road maintenance frameworks have been designed to promote innovation and encourage sustainable road maintenance.

Bear Scotland, the Ringway, Babtie Jacobs, Breedon Aggregates joint venture, will become responsible for overseeing 814 miles of trunk roads in the North West of Scotland taking over from incumbent Balfour Beatty/Mouchel’s TranServ joint venture.

TranServ will shift to the South West region taking over management of 443 miles of roads from Amey.

The two fourth generation frameworks are estimated to be worth between £130m and £160m and will support around 1,250 jobs across Scotland over five years.