She said her decision to stand down followed a lack of support from the press and UK Government.

Ms Becker, dubbed the Angel of Mostar for her humanitarian efforts in the Bosnian city, made national headlines in recent weeks after she was shot in the leg outside her hotel in northern Albania.

A Kosovan man inspects the wreckage of his home

The government also turned down her application for 87 visas for Kosovan refugees she was trying to bring into the UK for medical treatment.

Ms Becker, from Brighton, said she had been accused of seeking publicity despite choosing to stay with the children on the Albanian Kosovan border.

America has already received 25 of her evacuees and is issuing further visas for other patients in her care.

'I've lost faith in myself'

In a statement she said: "As a result of being unable to fulfil my promise to the patients destined for the UK I have lost faith in myself.

"Operation Angel will continue to operate without my involvement. I would like to thank each individual who has supported us throughout the past five years, enabling us to save so many lives."

Her spokesman, Mike Mendoza, said she would continue with her work privately and alone and had no intention of returning to the UK.

"She no longer feels British. She will carry on as an individual. She will do her own thing in her own way and will continue to help people on her own."

He said her current mission to get 90 Kosovan refugees out of Albania has finally succeeded with the Greek Government allowing in all 90 refugees in her care.

"Sally will go with them," he said. "Their visas are being processed at the moment so they will probably be going some time next week. Sally will then return to Albania."

Jack Becker: Negative portrayals in the press prompted resignation

Ms Becker's father, Jack Becker, said his daughter could not understand why the press had turned against her. "There she is out there helping children and all she gets is abuse from newspapers," he told BBC News 24.

While the States and Greece had accepted the children, England would not let them in even though, he said, it would not have cost the country "one penny piece".