A consumer group has begun a legal bid aimed at strengthening protection for owners of fire-prone tumble dryers.
Thousands of people with Creda, Indesit and Hotpoint dryers are awaiting repairs a year after a safety alert was first issued.
Now the consumers' association Which? is seeking a judicial review into what it regards as failures by the trading standards team overseeing the case.
Peterborough Trading Standards said the legal attempt was "premature".
Fires have been caused by excess fluff, which can catch on the heating element of these dryers. Some five million affected machines were sold in the UK between April 2004 and September 2015.
Whirlpool, which now owns the brands affected, has been running a repair programme and offering discounted replacements to anyone with an affected dryer.
Tower block fire
This campaign - rather than a full recall - was agreed with the trading standards department in Peterborough, close to Whirlpool's headquarters.
It advised customers that they could still use their machines, as long as owners did not sleep or leave the house when the dryers were on.
Yet a machine awaiting a repair caused a huge tower block fire in west London in August, leaving families homeless and requiring 120 firefighters to bring it under control.
The London Fire Brigade said it believed a faulty Indesit dryer had been the cause of the fire.
Now Which? has formally requested that the High Court consider whether Peterborough Trading Standards' handling of the case, since the London Fire Brigade's report into the fire, has been lawful.
Whirlpool freephone helplines: 0800 151 0905 for the UK, or 1800 804320 for the Irish Republic
"We believe that the way Whirlpool has handled the tumble dryer safety issue is absolutely appalling and to add insult to injury Peterborough Trading Standards has failed to do its duty to protect consumers," said Alex Neill, of Which?.
"We have decided to step in and take legal action because we want Peterborough Trading Standards to properly protect Whirlpool customers and carry out its role as an enforcer of product safety laws."
If the bid is successful, it could be months before any hearing commences.
There has been criticism of the speed of these modifications and of the company's advice that the machines can still be used as long as they are not left unattended.
At times earlier in the year, there were cases of people being told they must wait well over a year for an engineer to visit.
Following its calls for Whirlpool to speed up repairs, Which? now wants trading standards to consider enforcement action as part of a fresh review into the risks faced by owners of these dryers.
It claims that the case shows the difficulties local trading standards teams face when "standing up to big business".
Peterborough Trading Standards said that an independent review had started earlier this month.
'Number one priority'
"We would expect Whirlpool to fully comply with the outcome. This review involves independent experts in fire safety, product safety and product risk assessment," a Peterborough City Council spokesman said.
"We will strongly defend our position if Which? is granted a judicial review and bearing in mind the on-going independent review we consider that this action is premature.
"The safety of consumers is our paramount concern and has been throughout our involvement in this matter."
Whirlpool said earlier this month that it had repaired two-thirds of the machines registered for modifications, and that waiting times for repairs had been improved and could be as little as one month.
"The safety of consumers is our number one priority and we are committed to doing everything we can to ensure that the tumble dryer modification programme is carried out in a safe and timely manner," a spokesman said.
"We have acted entirely appropriately at every stage of this programme and refute any suggestion otherwise."