Dempsey has been at Ray O’Rourke’s side throughout the firm’s meteoric rise to its current status as the country’s largest private contractor.

He is one of three shareholders in the company alongside Ray and Des O’Rourke and a co-founder of the contractor.

A Laing O’Rourke spokesperson said: “Bernard Dempsey retired from his position as Deputy Chairman of Laing O’Rourke at the end of August after 33 successful years with the Group – and 10 years since the acquisition of the Laing Construction business.

“Bernard’s decision was entirely motivated by his desire to devote all of his time and energy to his family. His board-level duties have been assumed by the existing leadership of the Group.”

Dempsey’s retirement was confirmed as O’Rourke revealed that Olympic construction director Howard Shiplee will join the firm next month.

It is not thought that Shiplee will be a direct replacement for Dempsey.

One industry source said: “Bernard was very much a commercial man while Howard is more about the delivery of projects.

“Bernard has always been alongside Ray and he will be a massive loss to O’Rourke.”