A steel maker is to cut more than 350 jobs due to “challenging” market conditions.
Liberty Steel said about 282 jobs would go at its plants in South Yorkshire, and about 72 in Newport, south Wales.
The firm said it was consulting with trade unions and hoped to avoid compulsory redundancies.
Ross Murdoch from the GMB union described the losses “as more bad news for the UK steel industry”.
Downing Street said it was “monitoring the situation closely”.
The proposed redundancies include, 250 in Stocksbridge, 17 in Rotherham and 15 at Brinsworth in South Yorkshire, and 72 in Newport, South Wales. The firm said it employed just under 2,000 people at its South Yorkshire plants.
Liberty Steel said the job cuts follow a review of its UK business, leading to a decision to reduce its workforce at certain plants to match production forecasts.
The firm’s chief executive Cornelius Louwrens said: “Liberty has taken enormous strides in improving the performance of the steel mills it has acquired over the last six years. We’ve re-started mothballed plants and demonstrated a commitment to invest in the UK.
“Unfortunately, the steel industry in the UK is facing challenging conditions and we have made the difficult decision that there is a need to reduce the workforce at a handful of locations, in order to make them sustainable for the long-term.”
The firm took over the plants in Wales and Yorkshire in 2017 after it bought out Tata Steel’s speciality steels division for £100m.
It is the latest blow for the steel industry in Newport after Tata Steel announced plans to shut its Orb plant, near to Liberty Steel, in September 2020, putting up to 380 jobs at risk.
Mr Murdoch said: “A country that doesn’t produce its own steel for key infrastructure projects and shipbuilding is a country that’s destined to fail.”
“Our steelworkers deserve better than this. The government urgently needs to intervene and ensure steel companies in the UK receive the backing they have long called for on energy costs and business rates.”
The Prime Minister’s official spokesman said the government was in contact with Liberty and trade unions.
The spokesman said: “This is a commercial decision but Liberty Steel Group has reaffirmed their commitment to the UK market and to its Newport, Stocksbridge and Rotherham steelworks, and all those affected will be offered the opportunity to remain in the wider alliance the firm sits in by joining a new company.”
Labour leadership hopeful Rebecca Long-Bailey tweeted: “Extremely concerning that Liberty steel is set to axe hundreds of jobs.
“We need government to urgently step in to save this industry & implement a comprehensive steel strategy.”