Three NHS call centres are to close with the loss of 100 jobs, a leading union said today.
Unison said it had been told by managers at NHS Direct that centres at Ipswich, Norwich and Chelmsford will close.
Most of the jobs will be among qualified nurses, added Unison.
"We are really worried about the impact on patients," said a spokesman.
Unison said the move will not just hit East Anglia, but have a knock-on effect nationwide for patients relying on the call centre service.
Dave Prentis, Unison's general secretary, said: "This is a disaster for patients and staff and we are really worried that this is the thin end of the wedge.
"Although these cuts hit local areas, the knock-on effect will be felt across the country.
"NHS Direct staff are already pressed to breaking point during peak periods, when the call centres can deal with up to 30,000 calls a day. Less people on the phones will mean patients depending heavily on out of hours duty care and a rise in the numbers queuing at A&E.
"NHS Direct nurses will also struggle to find work elsewhere, with jobs being axed in the NHS.
"We call upon local MPs in the East Anglian towns affected to join us in urging the East of England Health Authority to reconsider its decision, as a matter of urgency. The Government must guarantee contracts for NHS Direct and the 111 emergency service, rather than rush through plans that will have huge consequences."