Lorenzo di Cretico, a manager at the central London restaurant and club 100 Wardour Street, moved to the UK 12 years ago with high hopes.

He had been a manager at a trattoria in Rome but wanted to learn English and said London “had always been my dream”. He found a waiting job within a week.

Now, however, Mr di Cretico is returning home. He has only worked for four months of the past year due to restaurant closures during the pandemic and, with little hope of venues reopening soon, decided to start his own delicatessen in Rome.

“After this Covid situation I see how the [UK hospitality] industry has been left on the side and I didn’t really like the way we have been treated,” Mr di Cretico said. “I feel a little bit let down.”

Mr di Cretico is one of an estimated 1.3m foreign born workers to have left the UK during the pandemic, of which 700,000 were in London, according to analysis of government data by the Economic Statistics Centre of Excellence, a research hub set up by the Office for National Statistics. Brexit has been a consideration but the pandemic has driven many away.

With government missteps over coronavirus support and a new variant spreading rapidly across the UK, community groups predict many will never return.

Sectors that have seen the greatest drops in non-UK staff are those most affected by the economic damage wreaked by the crisis. The ESCoE estimates that about 158,000 non-UK workers have left or lost jobs in the accommodation and food services sector, while more than 217,000 in the retail industry have gone. Manufacturing, construction and transport have also been badly hit.

The mayor of London’s office said that the capital had seen its largest increase in unemployment in 30 years, with non-British workers a “substantial proportion” of those affected.

Stefan Gonera lived in London for more than 20 years, working first as a labourer on building sites before setting up as a self-employed plumber. But when the pandemic struck, work dried up and he returned to Rybnik in Poland in August after going on a recce trip and being “impressed” by the situation there.

“I’m back working for a company and I am very happy with this situation,” he said. “I’m not thinking about coming back.”

Unions and community groups report a cocktail of reasons for the exodus. Some fell through the gaps for financial support during the pandemic, while others have feared that travel restrictions will isolate them from friends and family for extended periods. Mr di Cretico said that had Brexit not happened he would have considered staying “a little bit longer”.

Bar chart showing London losing the most non-UK workers of any other region

Maike Bohn, co-founder of the3million, which represents EU citizens living in the UK, estimated there were many people like Mr Gonera who feel their emotional and financial situations would be better served by returning home.

EU residents who had not yet attained settled status ahead of Brexit have struggled to access benefits and housing support, for example, she said. “The government Covid strategy failed them. These are people that would have stayed, could they have accessed help.”

There are also sector-specific issues. Dave Turnbull, the Unite union’s officer for hospitality, said that many migrant workers in areas such as the hotel industry lived in staff accommodation and found that as companies cut jobs they were evicted from their homes.

Nadyalka Boncheva, a trained textile machinist for Fashion-Enter, a not-for-profit garment manufacturer that supplies mainstream retailers such as Asos and N Brown, returned home to Bulgaria for Christmas and said that fear of catching the virus, particularly the more infectious strain, had kept her from returning to the UK.

“I want to come back and do my job. I love it,” she said. “But the pandemic is keeping me away. It’s the concern. It’s very bad at the moment in the UK.”

With widespread job losses across the sectors most affected by the drop in foreign workers, few businesses are concerned about the immediate prospects for short-term recruitment, particularly while many remain closed under the current lockdown regulations. But many company owners fear that the migrant outflows could cause an employment crunch when trading finally improves.

Ms Boncheva’s boss, Jenny Holloway, Fashion-Enter’s chief executive, said that 16 per cent of her 192 employees were from eastern Europe and several had not returned since Christmas. She had struggled to find skilled staff since Brexit as machinists were not given an exemption to immigration rules and fears that a rush in demand for clothes as lockdown lifts will leave her short staffed. Her hope is that an academy she has started will train enough machinists to plug the hole.

Kate Nicholls, chief executive of UKHospitality, the trade body, said that with 1m employees from the sector still on furlough, businesses do not know how many have gone home and will not return.

“Short term we will reopen with social distancing . . .[so] it will take time as we wind up gradually before you realise, hang on I’m short of workers,” she said. “If it is a permanent change we could find out that we are at a labour shortage point [as we were] in December 2019 before the pandemic.”

The British Retail Consortium, an industry body, said that it was “critically important” that EU workers felt able to work in the UK as foreign employees fulfilled roles with key skills such as pharmacists and data analysis that were “scarce in the UK labour market”.

Retail, manufacturing and hospitality are the three sectors that lost the biggest number of non-UK workers in the pandemic

Graham Watts, chief executive of the Construction Industry Council, said that many building sites were already operating below capacity, with some having lost more than 20 per cent of their workforce, while a survey published this month by manufacturing trade body Make UK found that a third of British manufacturers believed the country’s ability to attract international talent would decrease.

In industries such as retail and manufacturing the drop-off in foreign-born workers has been partly offset by an acceleration of automation, as companies grapple with higher costs, rising absence rates and customers’ desire to minimise human contact.

But in service industries such as hospitality, the shortage’s impacts risk being more acute.

Jeremy Goring, chief executive of The Goring Hotel in London’s Belgravia, said the pandemic had solved the lack of foreign workers in “the worst possible way”, but “if and when [business returns] there will be a HR bloodbath” that recruiting UK residents will not solve.

“Europeans are among the most skilled hospitality professionals around the UK and yet we have managed to make them feel really unwelcome,” he said. “That teaching by top class professionals was a big factor in getting UK people into the trade.”

This will change how restaurants, hotels and other “high touch” businesses that require human interaction operate, suggests Des Gunewardena, chief executive of D&D London, owner of 100 Wardour Street and Mr di Cretico’s former employer.

“It’s not today’s issue but it is tomorrow’s issue. We will have to run restaurants with fewer people and different working practices,” he said.

Additional reporting by Jonathan Eley, charts by Aleksandra Wisniewska