Concern over London GP list 'cleansing'
Concerns have been raised about the number of patients being wrongly deleted from London surgeries.
A least 460,000 names have been removed from GPs lists in the capital in the past five years, a Freedom of Information (FOI) request showed.
Lists are cut when surgeries cannot contact patients over a period of time.
But Londonwide Local Medical Committees (LMC) said people can become "really scared" when they discover they are no longer registered.
People would be dropped from a list if they had not spoken to a practice in six months and there was no response to at least two written requests, the Department of Health said.
"This ensures that GPs are not paid for patients who have moved out of the area and who are no longer receiving services from that practice," said a spokesperson.
"If patients are contacted and confirm they remain in the area, then they will remain on the practice list and continue to receive services."
But the LMC said names can vanish by mistake.
Dr Michelle Drage, from the LMC, said people may become upset when they try to book an appointment and are told they are no longer registered.
She said they could think they have done something wrong when this is not the case.
'Nature of London'
Patients who are wrongly deleted from lists must re-register to keep their doctor.
In the east London borough of Tower Hamlets, this was the case for 61% of those removed in a recent overhaul, the FOI documents showed.
Another 10,000 people had to do the same in nearby Newham in recent months.
Labour MP Emily Thornberry said the system had become "a real mess" because of the difficulty in keeping track of people moving around the city.
The former shadow health and social care secretary and MP for Islington South and Finsbury said people would not necessarily respond to letters from surgeries, particularly if their English was poor.
"In Islington, between the 2005 election and the 2010 election, there were 65% of the population who had moved.
"It's very difficult to keep up with people," she added. "It's the nature of living in inner London."