“I suppose the technical phrase is we’re screwed,” said Ruari McCulloch, owner of Pinstripes & Peonies, a high-end London florist, which counts several London department stores and the Paris Air Show among its clients.

Mr McCulloch is one of the many small business owners facing the toughest few months yet of the pandemic, starved of income for much of the past year as the UK approaches the anniversary of the first national coronavirus lockdown in March.

Cash levels are depleted and debt loads have risen fast for companies with high fixed costs but zero revenues, leading to urgent calls from the UK’s business lobby groups, including the CBI and the British Chambers of Commerce, for immediate and sustained financial support from the chancellor Rishi Sunak.

Mr McCulloch’s business was turning over about £150,000 per month before the pandemic hit supplying floral arrangements for conferences, hotels and museums but has only managed to secure £10,000 in grants since orders all but disappeared after the first lockdown began.

“I personally think the events industry is dead. It’s unbelievably depressing,” said Mr McCulloch, who has already remortgaged his house to keep his company going.

“Businesses are running out of cash,” said Kate Nicholls, head of UKHospitality, who estimates that only one in five businesses in the sector has enough cash to survive beyond February.

Simone Schehtman, co-founder of Teamworks Karting, warned that many small leisure businesses are struggling with the start-stop cycle of lockdowns and partial reopenings.

“Despite being closed, small businesses like us are still burning cash,” Ms Schehtman said. “Much of the sector is just falling over.”

With no end in sight for the latest lockdown, Ms Schehtman fears it will be some time before customers at her Midlands-based kart track company feel confident to return even with the rapid rollout of the vaccination programme in the UK.

Business groups have urged ministers to ensure there is support in place to match the pace of the economic recovery as a cliff-edge approaches at the end of March.

“There is no end date to restrictions and all support comes to an end on March 31,” said Ms Nicholls. Many companies will then face having to pay a year’s worth of rent, as well as full business rates and VAT, just as they are trying to woo back nervous customers.

She warned that many owners will “just throw in the keys” unless the government acts with urgency and produces an economic reopening strategy to give businesses the chance to plan.

Tony Danker, director-general of the CBI, wrote to Mr Sunak on Tuesday warning him of the “cliff-edge” in business support at the end of March that was “not in step with a phased reopening of the economy and the gradual return of demand”.

Many business owners are finding it increasingly hard to continue without clear guidance from ministers on how they plan to reopen the economy. “It’s really difficult now with no end in sight,” said Stephen Wallace, owner of three Bristol pubs, including the Golden Guinea.

He tried to claw back some revenues by opening for a few days before Christmas but instead racked up further losses as customers stayed away, forcing the pubs to pour away beer opened especially for the week. “December is when you make the money to see you through January to March,” he added.

The government responded to the latest lockdown with a new round of grants for the retail, hospitality and leisure sectors of up to £9,000. But Mr Wallace — like many others — is still waiting for a one-off £1,000 grant from December.

Matt Griffith, director of policy at the Business West Chamber of Commerce, said the gap between now and any recovery was “too large for many smaller firms, given the shortcomings of current support measures”.

“For those who have borne the brunt of the impact of Covid, we are moving beyond the ‘staying afloat’ to the ‘sinking below the waves’ stage of the crisis,” said Mr Griffith.

Mark Rowlands, founder of AV Production Services, which was having its best trading period ahead of the pandemic providing lighting and audio to conferences around the world, has had to sell his own car to bring in cash.

He has had no income since global events were cancelled in March and was not eligible for grants or furlough as he was a director of his company.

“I have assets of £350,000 to £400,000 but I can’t sell them as the industry currently does not exist. If the equipment does not sell, and there is no further help from the government, I could lose everything, including my house.”

The Federation of Small Businesses this month warned that more than 250,000 firms were at risk of going bust this year. In December, a survey by the CBI found a third of businesses only had cash reserves to last another three months.

After his recent bleak assessment on the short-term outlook for the economy, Mr Sunak is expected to announce more support measures in the Budget in March.

This sparked calls from businesses for a longer term package designed to keep their operating costs low: a furlough extension or job retention bonus would help keep wage costs down but they also want an extension of VAT and business rates relief and help with rent.

“There needs to be an ‘off ramp’ for Covid support,” said Tej Parikh, chief economist of the Institute of Directors, which is calling for a tapering of support schemes and cuts to national insurance contributions.

James Balfour, chief executive of the London-based fitness company 1Rebel, said an extension of the business rates holiday was “critical”. He fears habits will change and it will take longer to persuade members back.

The company broke even during the summer when it was permitted to open but with seven gyms in its portfolio “if on March 31 we get to reopen but we have to pay rates again [of] £80,000 per month . . . it will be very difficult”.