The company employed 15,312 people worldwide during the year to March 31 2014 with an annual wage bill of £835m.

O’Rourke undertook a company-wide salary review last year which saw 93% of staff in the Europe hub receive pay rises.

Data released in O’Rourke’s annual review shows that the group workforce consists of 6,033 office based staff and 9,279 site workers.

O’Rourke also has a fairly youthful staff profile with only 11% of employees over 55 with 40% under 35.

The company said: “As a direct employer, we remain committed to creating high-quality careers that enable our people to achieve their aspirations while bringing value to our business.”