Private company Serco is to be awarded a £140 million contract to provide community health services to 600,000 patients in Suffolk.
The firm has been confirmed as the preferred bidder to run the area's adult community services, specialist children's services and community hospitals, and is expected to take control within weeks.
Dr Paul Watson (pictured), chief executive of NHS Suffolk, said Serco had provided rigorous evidence of its experience as a service provider.
'We are confident it will ensure our patients continue to receive well-managed, effective services, with a constant focus on improving quality, and delivering value for money for the taxpayer,' he said.
But regional director of RCN Eastern Karen Webb said moving nurses out of NHS employment could affect terms and conditions.
'Those transferring from the NHS will do so under TUPE arrangements, which should guarantee terms and conditions. However, the government is looking at TUPE and how long they will be able to enjoy these is a a moveable feast.'
Tracey Lambert, UNISON Eastern region's head of health, said the decision was 'an ideological move, purely to save money. How much of that will be ploughed back into patient care and improving services and how much will go directly to Serco shareholders?'
Around 1,000 staff are expected to be transferred from the NHS to Serco under the deal; many had already faced upheaval under the Transforming Community Services programme, with some contracts transferred from Suffolk PCT to South Essex Partnership University NHS Foundation Trust as part of interim arrangements.
Ms Webb believes that a string of private companies could bid successfully for community contracts.
'The private sector has the ability to invest a lot more in contracting and tendering processes. Private firms produce professional pitches, and it can be very difficult for NHS organsiations to compete.'