Speaking at First Minister’s Questions this week, party leader Richard Leonard told parliament the party has evidence of umbrella companies charging workers to access their wages on the flagship Aberdeen bypass.

According to Mr Leonard, the practice sees money deducted from payslips and described as a ‘company margin’.

He also told how construction companies in Scotland use umbrella companies, including employment agencies, to pay staff working on government contracts, which allows them to dodge tax, cut costs and exploit workers.

In the case of the AWPR, workers employed on constructing the route have been charged to be paid their wages from a number of umbrella firms, including DLP Payroll Solutions, Labour added.

Workers have shared their payslips with Unite the Union, showing the “margin charge”.

Scottish Labour leader Richard Leonard said: “The SNP government is handing over millions of pounds of public money to these companies and they are treating workers shamefully.

“Redacted pay slips from workers on the flagship Aberdeen Western Peripheral Route project show that they were being charged for the privilege of being paid.

“Workers have been blatantly exploited on a contract funded by the SNP government. SNP ministers now must take steps to ensure this never happens again.”

A Transport Scotland spokesman said project bosses were not aware of it happening but had launched an urgent investigation.