The country's biggest union is calling on the government to give more money to the NHS, amid fresh protests across the UK against plans to cut services.
Treatment will be available despite the cuts, the government claims
Unison says the chancellor should use next week's pre-Budget report to help NHS trusts tackle financial deficits.
Royal College of Nursing (RCN) head Beverley Malone said she hoped changes to the service would be made for clinical, not just financial, reasons.
Protests are taking place against cuts in various UK locations.
These include demonstrations in Chertsey, Surrey, and Hatfield and Stevenage in Hertfordshire.
RCN general secretary Ms Malone told the BBC said she hoped the government would "take to heart" the NHS's clinical needs.
"The RCN's hope is that they will really take that to heart and make sure that there are clinical reasons that are driving these changes and not financial reasons.
"It shouldn't be on the back of patients that these changes are made," she said.
A senior consultant at a Kent hospital - who has resigned his managerial post because of plans to downgrade services - spoke at a rally in Mote Park, Maidstone, on Saturday.
Tony Hulse, a paediatrician for 18 years at Maidstone Hospital, joined other consultants among an estimated 2,500 demonstrators.
He resigned as deputy medical director over plans to move the hospital's acute services. He will remain a consultant at the hospital.
Earlier Health Minister Lord Warner told BBC News 24 he believed some NHS trusts were over-spending "recidivists".
"The NHS is providing good quality services to thousands of people, and it's the minority of trusts that have got some deficits that have got to tackle that problem, because some of them are recidivists, they've been over-spending for quite a few years, " he said.