Transport for Scotland said a “large proportion” of the £88m in subcontracts still to be awarded on the scheme will go to local suppliers.

So far £144m of subcontracts have been awarded on the major infrastructure project which will upgrade Central Scotland’s motorway network, including the completion of the M8 between Edinburgh and Glasgow and improvements to the M73 and M74.

The job is around 18 months into construction and scheduled for completion by spring 2017.

Cabinet Secretary for Infrastructure, Investment and Cities, Keith Brown said: “As one of the biggest transport infrastructure projects currently underway in Scotland, the M8 M73 M74 Motorway Improvements Project has attracted interest from specialist engineering firms all over the world, but equally, it’s great to see a local enterprises providing a service and benefitting from this Scottish Government investment.

The Scottish Roads Partnership joint venture of Ferrovial Agroman and Lagan is responsible for the design, build, finance and operation of the project.

It has confirmed that almost £150m worth of sub-contracts have been procured through the Scottish Government portal, Public Contracts Scotland, since the start of work in February 2014.