MPs are demanding to know why the white goods manufacturer Whirlpool ended a product replacement scheme for dangerous tumble dryers.
The Commons business committee says one million of the defective machines remain in UK homes.
Last week, a coroner blamed a fault in a Whirlpool dryer for a 2014 fire that killed two men in north Wales.
The firm says it is still offering free repairs, but ended a £50 offer for a replacement machine after demand fell.
The affected machines include dryers manufactured under the Hotpoint, Indesit, Creda, Swan or Proline brands between April 2004 and October 2015.
After problems with the machines first emerged, Whirlpool initially told customers that the dryers were safe to use but should not be left unattended, but later said the machines should be unplugged until they could be repaired.
With growing waiting lists for a repair, the company then said it would allow customers to purchase a replacement dryer for the reduced price of £50.
The Commons Business, Energy and Industrial Strategy Committee has written to Whirlpool, asking why it has now chosen to end this replacement scheme.
Committee chairwoman Rachel Reeves accused the US manufacturer of "falling significantly short of their responsibilities" and asked why boss Ian Moverly failed to mention the end of the replacement scheme when he gave evidence to her committee in October.
Whirlpool said anyone with an affected dryer was still eligible for a free repair, and should contact them immediately to arrange it.
It said in a statement: "After two years of extensive measures to raise awareness, the number of consumers coming forward has fallen sharply.
"This suggests that few affected appliances remain in service."
It told customers who still owned one of the appliances it was "never too late" to get in touch.
It continued: "Previously, consumers who wished to upgrade their products to a newer model were offered the additional option of a brand-new dryer in exchange for a small contribution to the total cost.
"The scheme has now ended due to a fall in demand."
The coroner from the inquests into the deaths of Doug McTavish and Bernard Hender in Llanrwst, north Wales, told Whirlpool that it had to "take action".
He said the fire was caused "on the balance of probabilities" by an electrical fault with the door switch on the dryer.
He described evidence presented at the inquest by Whirlpool as "defensive and dismissive" and said the company's approach was an "obstacle" to finding steps to prevent future fires.
His final report has been sent to the company, which has until 26 December to respond.
Consumer group Which? criticised both Whirlpool and the government, which it called on to step in.
The company's managing director of home products and services, Alex Neill, said: 'It is completely unacceptable that Whirlpool has shut down its replacement scheme for these dangerous tumble dryers.
"It is irresponsible that despite one million households potentially still using an affected machine, Whirlpool seems unwilling to do everything possible to deal with this issue.
"The government must step in and force Whirlpool to fully recall the remaining tumble dryers."