Simon Ellison, National Highways sector director, is set to leave the business this month.

It is also understood that Darren Dobson, highways operations director, will be leaving the business amid the management changes at the division, which accounts for around a third of Costain’s total revenue.

It is understood that Costain has confirmed to National Highways that Ellison is leaving but the firm refused to comment on Dobson’s rumoured planned departure.

Both Ellison and Dobson are Costain veterans having worked at the business for 25 years and 19 years respectively.

The management changes come during challenging times for the division with growing uncertainty about the pipeline of National Highways work.

Just last week Costain received news that its major central reserve contract for the M62 across the Pennines had been suddenly axed on the eve of main works starting.

National Highways managing director of the Smart Motorway Alliance Tony Slater blamed the sudden decision to axe the scheme on failure to keep projected costs within the spending budget.

Costain had been mobilising to start the massive 19-mile-long project to install a concrete central reserve.

Based on initial Costain pricing, the M62 J20-25 scheme at full scope was expected to cost 60% more than the available budget. Even after trying cuts to scope, Costain’s projected cost would be 10% above the available budget.