The identity of the new owner of British Steel is once again in doubt as the Official Receiver responsible for selling the business said it will start talking to other potential suitors.

The decision by the Government's Insolvency Service comes as two months of exclusive talks between the department and Ataer Holding ends.

The Official Receiver said: "While discussions with Ataer are continuing, discussions with other parties who have expressed continued and renewed interest in acquiring the whole British Steel business will now be possible.

"I have instructed the special managers to engage with these additional interested parties. Diligence team members from these parties are expected to visit the company's sites over the coming days and weeks."

Previous reports have suggested that investment vehicle Ataer, which is controlled by Turkey's military pension fund, is concerned at the lack of progress to push through price cuts with suppliers.

But the Official Receiver insisted: "Ataer remain very much interested in acquiring the business and we remain in detailed discussions with them to conclude a sale."

An unnamed source said it was felt that the receiver was putting pressure on Ataer to conclude the deal before the Brexit deadline of October 31.

The news is expected to cause concern among British Steel's 5,000 staff, including 4,000 at its plant in Scunthorpe, and a further 700 on Teesside.

The company is also indirectly responsible for 20,000 workers in the supply chain and produces around 2.5 million tonnes of steel a year.

Workington's TSP Engineering, based at Derwent Howe, is a wholly-owned subsidiary of British Steel, but operates as a separate business.

John Coughlan, chief executive of TSP, said: "We understand negotiations are carrying on positively and we are fully behind British Steel, which is also a customer of ours.

"We want to see them survive to see our business grow - it is business as usual here."

The Unite union has called on Business Secretary Andrea Leadsom to guarantee the Government's continued support for British Steel and honour previous commitments on research and investment necessary to facilitate the smooth sale of the steelmaker.

British Steel was put into compulsory liquidation in May after talks between previous owner Greybull and the Government collapsed, leading the business to be run by the Official Receiver.