The flying of St George's flags across the country are creating "no-go" zones for NHS staff, with some facing frequent abuse, health bosses have warned.
Several NHS trust chief executives and leaders have said staff feel intimidated by the national symbols, including when they make home visits.
The findings follow a survey conducted among senior managers, 45% of whom were extremely concerned about discrimination towards staff.
A leader of a trust said anonymously that there were safety issues around how they work in the community, with nurses regularly visiting patients in their homes alone.
He said: "You're going in on your own, you're locking the door behind you.
"I have been into homes with people who have been convicted of sex offences, and we go in and provide care to them.
"It can be a really precarious situation, and they [the nurses] handle that absolutely brilliantly.
"The autonomy and the clinical decisions that they make within that, I think, is fantastic.
"We saw during the time when the flags went up - our staff, who are a large minority of black and Asian staff, feeling deliberately intimidated.
"It felt like the flags were up creating no-go zones. That's what it felt like to them.
"You add that on top of real autonomous working, that real bravery of working in people's homes, with an environment... [where] it feels like it's an area that's designed to exclude them.
"Our staff continue to work in that environment, and I think they deserve our real praise and thanks as a nation, frankly, for doing that within those really difficult circumstances."
He added his trust had also seen "individual instances of aggression towards staff".
Another NHS trust leader said a member of staff, who is white and has children of mixed heritage, had asked some people putting up flags to move so she could park her car.
"The individuals filmed what was happening, and then followed her, and she continued to receive abuse over a series of several days, not because she objected to the flags, but because she disturbed them," they said.
"There are lots of stories like that. There are lots of stories where people have tried to take flags down outside of their own homes and have been abused and threatened as a consequence of that."
The leader said the "springing up of flags everywhere has created another form of intimidation and concern for many, many of our staff".
Daniel Elkes, chief executive of NHS Providers, which represents trusts, said: "The NHS has relied on overseas recruitment for a long time to ensure we have the right workforce.
"We have a really diverse workforce and without that you can't deliver the NHS.
"We are trying to recruit from the very places where we provide healthcare so the intake into the NHS is representative of British people from more diverse backgrounds."
Professor Nicola Ranger, the Royal College of Nursing's general secretary, said: "Following a summer of further racist disorder, it is little wonder a growing number of nursing staff report feeling unsafe, particularly when having to work on their own and often at night.
"The government and all politicians have to stop pandering to dangerous anti-migrant sentiments and employers must prioritise tackling racism and work with trade unions to develop stronger mechanisms to protect staff."
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A Department of Health and Social Care spokesperson said there was "no place for intimidation, racism or abuse in our country or our NHS", adding that threats and aggression should be reported to police.
They said the government valued the "diversity of our NHS", and that workers "must be treated with dignity and respect".
"Our flags represent our history, our heritage, and our values," they said. "They are a symbol of our nation and belong to all of us - not just some of us."
The survey findings come ahead of strike action by resident doctors over pay and jobs due to take place on Friday for five days.
(c) Sky News 2025: St George's flags are creating 'no-go zones' for NHS staff, health bosses warn
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