UK workers are facing a "miserable Christmas" without a furlough extension, unions have warned.
Unite said the government must consider an extension of the job retentions scheme after it closes in October, amid warnings hundreds of thousands of jobs could be lost next month.
It comes as Office for National Statistics (ONS) figures on Tuesday revealed unemployment reached 1.4million in the three months to July, as the UK was forced into lockdown.
In the past three months alone, more than 695,000 employees fell off UK payrolls.
Unite said workers are facing a bleak winter without targeted support for employers after October 31.
It said without an extension, Chancellor Rishi Sunak risks opening the "redundancy floodgates".
Last week, the Treasury Select Committee said the government should consider a targeted extension of the scheme.
However, the Chancellor has repeatedly rebuffed calls for an outright extension.
A Treasury spokesperson said the government had "not hesitated to act in creative and effective ways to support jobs and we will continue to do so".
Employers looking to axe more than 100 workers must give workers 45-days' notice in the UK.
This starts on Wednesday for those looking to shed staff before furlough closes on October 31.
In total, nine million people have been furloughed for at least one three-week period since March.
The most recent figures suggest one in eight workers are still on furlough as businesses such as nightclubs and theatres remain closed.
Unite said that without "a clear and urgent sign" from the government that it was responding to calls to extend the scheme, it feared that "employers facing short-term struggles will issue redundancy notices".
Unite general secretary Len McCluskey said a signal from the government would "put a floor under struggling employers who are working hard to stabilise in the face of immense challenges".
"This week will mark 45 days until the job retention scheme comes to an end. With no sign yet of your government moving to extend or modify the scheme, there is the very real fear that this landmark will open the floodgates for redundancy notices as employers seek to comply with the 45 days’ notice period," McCluskey wrote in a letter to Prime Minister Boris Johnson."
Chancellor Rishi Sunak has said his priority is to find new ways to protect jobs.
A Treasury spokesperson said: "The furlough scheme has done what it was designed to do - save jobs and help people back into employment."
The spokesperson said the government had made "unprecedented interventions", including firms being given £1,000 for every furloughed worker still employed in January, business rates holidays, VAT cuts and the Kickstart scheme, which gives young people jobs experience.
