More than 900,000 small businesses are at risk of going under, according to new research backed by former Prime Minster Gordon Brown.
For business owners like George Ktori, time is running low as he is still paying bills despite his restaurant closing its doors.
"We are very worried about how we can survive," he said.
His staff includes husbands and wives who work together, and who will both lose their jobs if his firm collapses.
"The hardship is not just for us, it's for everyone," he said.
As support schemes like furlough and business loan programmes end, companies are at risk of insolvency, according to the Centre for Economic Performance (CEP) at the London School of Economics and the Alliance for Full Employment (AFFE).
Companies with 10 staff or fewer are particularly close to the edge, said the report.
"If we are to save good small businesses that are innovative and forward looking but which, without help with their investment plans, are in danger of going under, the Budget must bring forward measures.," said Mr Brown, who founded the AFFE last year.
Mr Brown urged the government to construct a long-term business recovery plan.
Mr Ktori, who owns Yamas Meze and Tapas in Nottingham, employs ten staff, says his business is making 10% of the sales it had done prior to COVID-19, through takeaways and meal boxes.
He took out a Bounce Back loan, designed for small businesses, "but that's only gone so far," he said.
He is now considering the larger, and pricier, Coronavirus Business Interruption Loan Scheme (CBILS) loan.
Kelly Hooper, owner of beauty and wellness salon The Barn in Somerset, is making money through selling some products online, she said.
"It's hard," she told the BBC. "This month is really, really hard."
"Any longer and there's a chance we won't be able to survive, unless we go into further debt."
"The online business has been ok, it's allowed us to survive," she told the Today programme. "Where we struggle is we have a bricks and mortar place. We have rent, insurance, lease hire of machines, we have that base we have to pay out whether we are open or closed."
Earlier this month Chancellor Rishi Sunak said that businesses in retail, hospitality and leisure will receive new grants to help them keep afloat until spring, worth up to £9,000 per property.
Business groups welcomed the new help as a good start but warned the money still wouldn't be enough to save many firms from collapse.
The help is in addition to business rates relief and the furlough scheme, which has been extended until the end of April.
Mr Ktori expects this money - £6,000 in the case of his business- to be paid at the end of the month. It will immediately be swallowed up by that month's rent, he says.
Much of the support business are relying on is in the shape of loans.
The option to swap that debt for a stake in struggling businesses should be considered, the report said.