Two out of five EU citizens living in the UK have concerns over job security with Brexit on the horizon, with particular concern felt by those in the construction, manufacturing, retail and hospitality sectors, a survey of FT readers has found.

The results, from a survey conducted two months after the June 23 referendum, highlight the doubts facing EU nationals over their future in Britain as Theresa May, prime minister, has so far refused to guarantee the rights of citizens from the bloc before formal negotiations begin.

This week Michael Howard, the former Conservative leader, called on Mrs May to end the “dreadful uncertainty” and urged her to “lead by example” rather than waiting for EU nations to make the first move over assurances about the status of British citizens living abroad.

In a reflection of the unease caused by the Brexit vote — and a rise in “hate crime” and anti-immigration sentiment — nearly a quarter of those polled said they no longer felt welcome in the UK, while a fifth have firm plans to leave the country within the next two years. A further 39 per cent are considering leaving the UK but have not fully committed to a move.

The majority of respondents were from longstanding members of the EU, including Italy, Germany, France and Spain, and the largest single professional contingent — 27 per cent — work in financial services. Others are employed in fields such as technology, healthcare and academia.

The responses indicate a mixed approach from companies to managing staff post-Brexit. Only 18 per cent of those surveyed were fully confident that their jobs were secure, versus 41 per cent who were anxious that their employment was in jeopardy.

Within certain sectors — such as construction and manufacturing, retail and hospitality, and media and entertainment — more than half of respondents were worried about their jobs. Overall, just under half of people reported having had no communication at all from their employer to discuss their immigration status since the referendum.

While it is unclear what visa conditions will be open to EU migrants already in the UK, it is expected that those who have been in the country for at least five years will be eligible for permanent residence. Still, experts have warned that a rush to register such applications in the run-up to Brexit could overwhelm the Home Office and be subject to significant delays.

Will Higham, director of campaigns at the business lobby organisation London First, said he saw companies across the capital, especially start-ups, concerned about their highly skilled EU workers feeling unwelcome. “It creates needless business uncertainly and human pain,” he said. “The government has to make an early decisive move that spreads confidence and certainty for employers and employees, and not hold on to them like a bargaining chip.”

Among the 732 readers who took part in the survey, some gave more detailed explanations of their experiences of living in the UK in recent months. One Spanish national working in tech, who has been in the country for the past 16 years, reported a “big feeling of being unwelcome”.

“I have been called an immigrant when my country has 10 times more British immigrants,” he said. “My country has to support 10 times more British immigrants in Spanish hospitals [than the NHS does]. On top of this, every time I go to a British hospital I meet Spanish nurses and doctors. British society has changed, and I don’t feel part of it any more.”

Having lined up a new and better-paid job back in Spain he relocated with his family this summer.

A Dutch national, who has been in Britain for more than a decade, said he had been subjected to “overt hostility from random people on the street” when speaking on the phone in his native language. “I have experienced the whole gamut of comments from . . . ‘go back to where you came from’ to threatening [and] abusive shouts,” he said. “I have started two companies in the UK, both of which I am either closing or moving to the continent.”

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A German financial services worker reported similar incidents, saying that his children had been called Nazis by British youths. “We have been asked in aggressive tones whether we are speaking Polish several times when speaking German on public transport,” he said. His company is now moving him and his family back to mainland Europe.

However, one Greek national working in retail insisted he was not worried about the impact of Brexit, saying: “I have faith and trust that the [UK] government will do everything necessary for me to carry on being here after paying taxes for 10-plus years.

“I do not necessarily feel that — leaving aside the racism drama — leaving the EU is a bad thing. The EU has been anything but good to my country.”

The rise in allegations of racist abuse has been noted in official figures. This month, the Home Office published data showing that reports of hate crimes motivated by race or religion had soared 41 per cent following the referendum, as the public debate surrounding the poll sparked a rise in anti-immigration sentiment.

Barbara Roche, a former Labour immigration minister and chair of the Migration Matters Trust, said the survey results were “very worrying” and echoed some of the concerns that she had heard from people in business. “The UK cannot afford to lose people with these skills and talents,” she said.

Ms Roche urged the government to “state unequivocally” that EU citizens would be able to remain in the UK post-Brexit, and called on ministers to “keep restating” that there was no room for abuse of migrants and foreigners in British society.