The government is to order an “unprecedented” recall of up to 500,000 Whirlpool tumble dryers – four years after fire safety concerns were first raised.

The move is a dramatic escalation in a long-running controversy involving the company’s “fire-risk” tumble dryers, and its handling of an issue that may have left dangerous machines in UK homes.

Kelly Tolhurst, the business minister, said: “Consumer safety is a government priority. We have informed Whirlpool of our intention to serve a recall notice. This is unprecedented action.”

The company issued a safety warning in 2015 after it found its Hotpoint, Creda and Indesit dryers had a fault which could make them catch fire, and it launched a programme to modify faulty machines. The company has faced heavy criticism over its decision not to recall items that are at risk of bursting into flames.

The government has previously said that this safety issue affected more than 5m tumble dryers manufactured and sold in the UK. There was a risk that lint could build up around the rear drum seal, fall on to the heater, ignite and cause a fire, it said.

Last month the government’s Office for Product Safety and Standards (OPSS) said there were an estimated 500,000 Whirlpool tumble dryers still awaiting modification.

The Labour MP Rachel Reeves, who chairs the Commons business, energy and industrial strategy (Beis) committee, said: “Finally the government is at last showing some teeth and taking long overdue action on Whirlpool.”

Reeves said Whirlpool had “proceeded at snail’s pace, leaving up to half a million unmodified and potentially unsafe tumble driers still in people’s homes”.

A Whirlpool Corporation spokeswoman said in a statement: “Safety is our number one priority and we remain committed to resolving any affected tumble dryers that have not yet been modified.”

It added: “The crucial message to anyone who still owns an affected dryer and has not already had it modified by Whirlpool is to contact us immediately on 0800 151 0905. In the meantime, anyone with an affected dryer that has not been modified should unplug it and not use it until the modification has been completed.”