The chief executive of Burger King UK has said the fast-food chain has not made its rent payments for April.
Alasdair Murdochtold the BBC's Today programmethat he could not see the firm paying for some time to come.
Burger King is one of several High Street restaurant chains to have asked the chancellor for a nine-month rent holiday during the coronavirus crisis.
Without it, some two million hospitality jobs are at risk, warned bar owner Jonathan Downey.
As well as Burger King, Mr Downey has persuaded bosses at other chains such as Wahaca and Nando's to back his plea.
"The idea is fairly simple and won't cost the taxpayer a thing," Mr Downey said.
No-one in the industry "expects to get back to anything like normal until mid-2021 at the earliest," he said.
"Without some extraordinary next measures we estimate that more than half of hospitality businesses and as many as two million jobs will not survive," he warned.
Burger King has more than 500 UK restaurants and Mr Murdoch warned last month the chain would be withholding rent payments.
He said: "It looks very difficult for us to be saying that we're actually going to be paying next month's or even next quarter's rent, because we have no sales.
"And I think that's the same for a lot of people in the industry."
He added: "I think the landlords are perfectly sympathetic, but there are also evidently ones who are reasonably threatening when they come back to us as well."
Under Mr Downey's idea - called the #NationalTimeOut - the next nine months' rent would be pushed back so that restaurants pay nothing until the first quarter of 2021.
"Leases are extended by nine months so that those payments aren't lost, just postponed to the back-end," said Mr Downey, who owns bars Milk & Honey and London Union in the capital.
Landlords would be helped too, under the plan, "with the same push back for them on the next nine months of their loan repayments".
The proposal includes other protections and support for landlords but the measure should only apply to businesses that have been forced to close by government order, said Mr Downey.
"It is now clear that hospitality businesses, having been the first and hardest hit by the virus, will now be the last allowed to reopen."
The letter to the chancellor has been signed by 14 other restaurant bosses and supported by trade associations such as UK Hospitality, the Music Venue Trust, the Night Time Industries Association and UK Active.
"Rents are a major issue for hospitality businesses - arguably the biggest threat at a time when most have no revenue," said Kate Nicholls, chief executive of UKHospitality.
"We need to come up with a solution to this collectively, to ensure that hospitality businesses, who have already been battered, don't have to suffer more than their fair share."
The business bosses that have co-signed the plea come from Burger King, D&D, Dishoom, Gordon Ramsay Group, Gymbox, Harts Group, Hawksmoor, JKS Restaurants, Leon, Living Ventures, Nando's, The Breakfast Club, Tortilla, and Wahaca.
"While the existing measures being taken by the government go some way to offer a lifeline to our industry, it's crucial that support and protection is extended to landlords as well as tenants of commercial premises, in order to help ensure a return to normality in the hopefully not-too-distant future," said Mark Selby, chief executive of Wahaca.
Some major landlords, like Canary Wharf Group, have also confirmed they support the plan. However, Melanie Leech, who runs landlords group the British Property Federation, said missing out on nine months' rent would be a significant loss for an industry that has a rent bill of £2.5bn each quarter.
But Mr Downey said: "It's a solution that allows businesses to work through the next nine months towards a bounce back and without the need for another government handout."
"We have to find a way to make this work for everyone and, although this is early stages, it feels like an answer."
A government spokesperson said: "We've taken action at unprecedented speed to support businesses, jobs and our economy through these challenging times. This includes targeted support for the hospitality sector with business rates holidays and cash grants of up to £25,000 for eligible firms.
"Pubs and restaurants can also benefit from our other business support measures, including the coronavirus job retention scheme, VAT deferrals and protection from eviction for commercial tenants affected by coronavirus.
"We would encourage any business that is struggling to find out more about the support available to them on gov.uk/business-support."