India’s Tata Steel plans to sell its loss-making UK business, putting the jobs of thousands of workers at risk.

Its European holding company has been told to “explore all options for restructuring”, including the partial or entire sale of its UK operations.

Union leaders travelled to Mumbai in a bid to persuade Tata to keep making steel at plants including Port Talbot.

The UK and Welsh governments said they were working “tirelessly” to ensure the future of the British steel industry.

Tata’s restructuring decision, which was announced after a board meeting in Mumbai on Tuesday, will also affect workers at its other UK plants including Rotherham, Corby and Shotton.

Tata said trading conditions had “rapidly deteriorated” in the UK and Europe due to a global oversupply of steel, imports into Europe, high costs and currency volatility.  Steel demand is still falling. It peaked in 2013. It is very hard to see who would the steel making end itself, although the rolling mills are more attractive.

In a joint statement, the UK and Welsh governments said: “We remain committed to working with Tata and the unions on a long-term sustainable future for British steel-making..

Unions expressed concern at the announcement and urged Tata and politicians to work at finding a buyer for the business.

Tata Steel has been operating in the UK since 2007 when it bought Anglo-Dutch steelmaker Corus.

In January the company announced more than 1,000 UK job cuts, including 750 in Port Talbot, where it employs 4,000 staff and a further 3,000 contractors and temporary workers.

And last October Tata Steel said nearly 1,200 jobs would go at plants in Scunthorpe and Lanarkshire.

There have been allegations that Chinese steel is being “dumped” on world markets at prices that UK plants cannot hope to compete with.

At the same time China’s economy has remained sluggish, meaning that its need to export has grown as the demand for steel from its construction sector weakens.