A private company which last month took over the running of community healthcare from NHS Suffolk is to cut 137 health jobs.
Serco's three-year contract, worth £140m, to provide services including community hospitals began on 1 October.
The company said its proposed plans for a new way of working would see 227 roles cut but 90 roles created.
The union Unison said it was "deeply worried" about the affect the staff cuts would have on the level of care.
Tim Roberts, from Unison, said: "We warned at the time that the only way they would be able to deliver the contract would be by making drastic cuts and that's exactly what they are now proposing.
"We fear that the true impact of these changes on service delivery will only become apparent once staff have left and it's too late."
'Invest in technology'
Serco runs the community hospitals in Aldeburgh, Felixstowe and Newmarket and also looks after speech therapy and specialist dental services.
Subject to a 90 day staff consultation, the 137 jobs would come from 795 full-time equivalent roles.
Paul Forden, managing director of clinical healthcare, said the planned changes would allow Serco to invest in technology and improve efficiency so clinicians could spend more time caring for patients.
He said: "As part of our new approach we will need to change the way our staff work and are now starting consultations about proposals that would mean that there would be an overall reduction of 137 posts at Suffolk Community Healthcare.
"Wherever possible, we would look to redeploy staff into these new roles.
"We would not be making any compulsory redundancies among frontline clinical staff and will do everything we can to minimise the number of non-clinical staff affected by the changes."
Mr Forden said staff would be consulted about the proposed changes over the "coming months".
Tracy Dowling, NHS Suffolk's director of strategic commissioning, said patients would receive "improved levels of care" under Serco's plans.
"The new model of care will see the increased use of new technology, changes to the way staff work and a reduction in bureaucracy and administration," she said.
"This will result in a more streamlined and efficient community health service and will deliver benefits for the patient and better value for the taxpayer."