CIVIL servants have been accused of acting "irrationally and unlawfully" in rejecting a bid by a major construction firm for a £350 million road maintenance contract.

Transport Scotland, the national transport agency, has been forced to suspend signing two major contracts for the maintenance of 1250 miles of road in the west of Scotland following a court challenge by Amey.

It is not yet clear who will take over the vital road maintenance duties next April 1, though Transport Scotland said it was in the process of finalising "robust contingency plans".

A bid by Amey to win the maintenance contract for north-west Scotland included quotes for 2312 jobs, of which 1513 were priced at 1p, according to a submission by the company to the Court of Session.

These costs are believed to be for tasks such as grass cutting, tree-felling and replacing street lights.

Transport Scotland rejected the bid after concluding that it carried "significant unacceptable risks" and was not "economically viable nor sustainable".

In its rejection letter, Transport Scotland estimated that Amey would have had a shortfall of £123m, according to the company's own estimate of the income it needs.

Last month, the government agency announced that it would appoint rival firm Bear.

A similar contract covering trunk roads and motorways in the south-west of Scotland has also been suspended, which Amey also currently holds.

Amey argues that Transport Scotland acted unlawfully and irrationally in awarding the contract to Bear as it did not consider the guarantee put in place by Amey and parent company Ferrovial, the Spanish infrastructure firm which also owns Heathrow, Glasgow and Aberdeen airports.

A spokeswoman for Transport Scotland declined to comment on the details of the legal case but said that ministers would "rigorously defend" it.