All 1,050 workers at the Kier Sheffield subsidiary were sent a letter warning them of the job losses.

A Kier spokeswoman said: “As a result of the current economic downturn, Kier Sheffield is in consultation with trade union representatives regarding a reduction in staff numbers by approximately 50.

“We will do everything we can to help those affected secure work elsewhere in the business wherever possible. We do not expect this to impact on our service delivery.”

Kier staff contracted to manage Sheffield Town Hall and other council buildings are on a separate contract and are unaffected.