News of the dispute follows last month’s announcement that the completion date for the bypass had been pushed back until late autumn.

That delay to the £745 million project was blamed on recent cold weather and Storm Frank in 2015, as well as the collapse of construction firm Carillion in January.

Now, talks are now under way to resolve the current pay issue, with local politicians calling for the matter to be investigated “as a matter of urgency”.

According to the local Press & Journal newspaper, the workers, who are believed to have been working on the Rothnick site outside Portlethen, are employed by subcontractor Rossmore Civils.

The reports state that the AWPR Construction Joint Venture is currently holding discussions with the firm to attempt to resolve the issue.

A Transport Scotland spokeswoman said: “The contractor has confirmed that AWPR Construction Joint Venture (the CJV) has subcontracted with Rossmore Civils to supply plant and workers to carry out various activities on the project.

“We are aware that a small number of operatives ‘downed tools’ this morning in dispute with their employer and the CJV is holding discussions with Rossmore Civils to establish the cause and resolve the matter.

“The CJV has also assured us that it is making all payments to the firm in accordance with the terms and conditions of their subcontract.”