The move will see utilities work concentrated in Dartford and Manchester as the St Neots office is dedicated to the company’s Select Plant business.
The move has stunned staff in Cambridgeshire who claim they are being left in the dark by head office.
One employee told the Enquirer: “It’s like a bloodbath here. Even the top guys are disappearing with little or no notice.
“There’s been no communication, just new departures being heard about every day.
“Everyone has been put on consultation from the directors downwards with tendering and estimating staff among the first to go.”
The Enquirer understands a raft of managers below utilities managing director Martin Bradbury has left the firm.
O’Rourke insisted the company was still committed to the utilities sector where it has ongoing contracts with major clients including Thames Water, UK Power Networks, Severn Trent Water and Scottish Water.
A spokesperson said: “We remain committed to the utilities sector with a focus on the delivery of water, waste and power network infrastructure.
“The business continues to be headed by Martin Bradbury with the key business winning functions being focused in either our Dartford or Manchester offices where members of the team are being given the opportunity to re-locate.
“The St Neots office has in fact been recently refurbished and will be dedicated to Select Plant.”
O’Rourke insiders said they believe the move was down to a focus within the firm on promoting contracts using products from its new Explore offsite factory in Nottinghamshire.
One worker said: “There is a firm instruction from the top that the huge investment in the Midlands precast factory means that only jobs that can be seen to make extensive use of pre-fabricated components can now be pursued.
“The unrelenting message is ‘feed the factory’.”
The O’Rourke spokesperson said: “We have made no secret of our plans to put our Design for Manufacture and Assembly agenda at the front and centre of our client propositions and we have aligned our operations with this approach.
“Beyond this we are not going to comment on speculation or provide details on specific individuals or commercial relationships.”