His shock departure comes just three months after he was promoted to head the construction division replacing Mace veteran Gareth Lewis.

Before becoming construction CEO in July, Jackson was chief operating officer having joined Mace in 2015 after 26 years with Laing O’Rourke.

His departure leaves Group Deputy CEO Jason Millett in temporary charge of the construction division while the company looks for a successor.

A company statement said: “Mace Group has announced that Andrew Jackson, CEO for Construction, has decided to step down from his role for personal reasons.

“Jason Millett, Mace’s Group Deputy CEO, will take up a temporary role as interim CEO for the Construct Engine, supported closely by Construct’s Chief Operating Officer Stephen Jeffery, and the business unit managing directors, while the Group undertakes a process to appoint a successor.

“Jason will combine the role with his current position as Deputy Chief Executive, and his transition to Group Chief Executive will continue as planned in January.”

Mark Reynolds, Mace’s Group Chairman and Chief Executive, said:  “I would like to thank Andrew for his hard work and commitment over the last nine years, supporting and leading Mace Construct through a period of major growth.

“He has made a hugely positive impact on our teams, has made a significant contribution to our construction business and leaves a real legacy. We wish him well in the future.”