Video report by ITV News Tyne Tees reporter Julia Breen
The government is being urged to protect around 250 jobs at Liberty Steel's pipe mill facility in Hartlepool.
Liberty Steel employs around 5,000 workers at sites around the UK.
Ministers have rejected a request for a £170m bailout to pay operating expenses and deal with recent losses, according to PA media.
Concerns over the future of the firm have grown since its financial backer, Grensill Capital, went into administration.
James Rambsbotham, chief executive of the North East England chamber of commerce, said the government should "do everything possible to maintain this viable business here in the North East."
Unite's assistant general secretary Steve Turner, said: "No option should be ruled out in protecting the long-term future of Liberty Steel, and that must include the option of nationalising the business."
A government spokesperson, said: "The government is closely monitoring developments around Liberty Steel and continues to engage closely with the company, the broader UK steel industry and trade unions."
"The government has supported the steel sector extensively, including providing over £500m in recent years to help with the costs of energy."