The firm has started consultation with the 150-strong workforce at its Station Road infrastructure division site which specialises in bridges.

It has also revealed it is looking for a buyer for its specialist renewables factory at another site in Chepstow, where 180 people are employed.

The proposal follows a comprehensive review of the Mabey Bridge business and will effectively see the firm pull out of traditional heavy bridge construction

The steelwork contractor said it was confident the proposed changes will help build a stronger, more sustainable future for Mabey Bridge’s modular bridge business in Lydney in Gloucestershire.

The firm presently employs around 130 staff at the site and some may be transfered over when the Chepstow head office closes.

A spokesman said: “We regret to confirm that we have informed our employees today of the proposed closure of the Mabey Bridge Infrastructure division at Chepstow.

“We also told employees that we have taken the very difficult decision to prepare the Renewables division and the Newhouse site for sale.”

He added: “We have not made these decisions lightly and we understand that this is a very difficult time for our people.

“Their welfare is an important concern for us and we will provide them with as much support as possible over the coming weeks.

“A full consultation process will now be conducted with all those affected and we will provide them with as much information as possible.”

He said that Mabey Bridge was hopeful that it would find a buyer for the Renewables division at the Newhouse site, who would provide the necessary investment to support this business in the long-term.

He said: “Like many companies we are forced to consider every possible option to remain competitive in difficult times.”