The firm reported steady trading for its year-end with profit predicted to be slightly ahead of expectations.

Leo Quinn, Balfour Beatty group chief executive, said the firm’s order book was expected to top £14bn, over 10% higher than last year.

This did not include work won on the HS2 civils or station contracts, which remained on hold waiting for the full project to be given notice to proceed.

In an upbeat trading update, he said: “We expect to deliver another year of profitable managed growth in 2019.

“The growing order book and strong balance sheet demonstrate our progress in positioning the group well to deliver increased value to shareholders.”

Quinn added that average monthly net cash was now forecast to be around £310m, ahead of the previous £300m guidance and above the 2018 figure of £194m.

In the United States Balfour confirmed that legal investigations were ongoing into allegations of falsified maintenance records at a US Air Force base had now been extended to include all 21 US Air Force bases managed by its Balfour Beatty Communities business.

Quinn said that Balfour Beatty did not condone the falsification of records and took the allegations made in the media extremely seriously.

He added that the firm continued to work with the appropriate authorities and military services to ensure a complete and thorough investigation.