Liberty Steel s future is the subject of speculation after specialist bank Greensill Capital went into administration.
Greensill Capital was the main lender to Sanjeev Gupta's GFG Alliance which includes Liberty Steel - the owner of steel plants across the UK.
Mr Gupta's business empire employs around 5,000 people in the UK, a majority of whom work for Liberty Steel across its 11 sites throughout England, Scotland and Wales, including Hartlepool, Scunthorpe, Newport and Rotherham.
Liberty Steel employs 250 people at the firm’s Hartlepool pipe mills in Brenda Road.
In a statement released on Tuesday, March 9, GFG Alliance said Greensill Capital filing for administration has created a ‘challenging situation’ but stressed the business currently has adequate funding.
Speaking to the BBC, the Shadow Business Secretary said the Government needed to explore every option to keep the company afloat, including nationalisation.
He told the broadcaster: "These are crucial jobs for communities up and down this country.
"Let's hope that Liberty Steel can find the refinancing that it's looking for but the Government needs a Plan B to make sure whatever happens, these jobs are saved.
"If there's one lesson we learned from this pandemic it's that our strategic infrastructure, our resilience really matters. And steel is a key part of our strategic infrastructure and resilience.
"We cannot afford to let these jobs go. Government has got to make sure it doesn't happen."
Mr Miliband's comments come days after Business Secretary Kwasi Kwarteng said he held "constructive" talks with union leaders to discuss Liberty Steel's future.
He tweeted on Friday: "I continue to monitor developments very closely and work to build a strong, sustainable steel sector in the UK."
On March 9, GFG Alliance said: “We will continue to work closely with the unions and our employees to identify the most effective ways of supporting the business and preserving jobs.
“GFG Alliance as a whole is operationally strong and we are benefiting from a thirteen year high in steel prices as well as strong markets in aluminium and iron ore."
GFG Alliance said chairman and CEO Sanjeev Gupta had a productive meeting with unions to discuss plans to make the parts of the UK businesses more financially sustainable and address the Greensill disruption.