The £250 million deal will see Network Rail and its contractors electrify the main line between Scotland’s two biggest cities, complete route clearance works at Winchburgh Tunnel, rail infrastructure works at Glasgow Queen Street and Edinburgh Waverley stations and extend platforms at Croy, Falkirk High, Polmont and Linlithgow.

A Scottish Government-funded investment worth £742m, EGIP is delivering a rolling programme of electrification across the central belt – reducing journey times and boosting capacity on routes including the Edinburgh-Glasgow Queen Street (via Falkirk High) line.

Network Rail will complete the main Edinburgh-Glasgow electrification works in 2016 and this phase of the programme will be complemented by the construction of the new Edinburgh Gateway Interchange station at Gogar and the subsequent redevelopment of Glasgow Queen Street station.

Piling works, to create the foundations needed to erect the overhead power lines, began this week and will be completed by the summer of 2015.

Transport minister Keith Brown said: “This £250m contract marks a significant milestone in the EGIP project, which will provide 20 per cent quicker journey times, 30 per cent more capacity and a complete overhaul of stations in both cities, with the new-look Haymarket station already completed on time and under budget and the planned transformation of Queen Street station into a 21st century transport hub.

“The Scottish Government’s record levels of investment in our railways is achieving even more than improved train journeys. It’s providing jobs and training opportunities such as those in the Babcock Training Facility in Hamilton where we are making this announcement.

“That is, in turn, contributing to Scotland’s growth and the sustainability of our engineering sector, as well as a bright future for the young people here setting out on a career path in the rail industry.

“This announcement signifies a massive step forward for EGIP, for Scotland’s railways and for many benefits far beyond.”

Rodger Querns, Network Rail programme director for EGIP, added: “EGIP is a unique chance to modernise and enhance our railway and transform rail services across the central belt. It is transformational in its scope and scale and will herald a step-change in the nature of our railway infrastructure, its resilience and reliability.

“The alliancing structure being used to deliver the electrification works will allow us to increase efficiency within the programme and deliver best value for money for the Government and taxpayer.”

The work now getting underway builds on the successful delivery of the £80m electrification of the Cumbernauld line and the transformational, £25m redevelopment of Edinburgh’s Haymarket station, both completed earlier this year.