The nurses' union is sceptical of claims Southern District Health Board cost-cutting will not affect patient care.
The board has said it has to cut costs in part to afford capital charges for the as yet unconfirmed Dunedin Hospital rebuild.
Last week it revealed its forecast deficit was now $13.9 million, nearly $5 million over budget.
New Zealand Nurses Organisation industrial services manager for the DHB sector Lesley Harry said when chief executives approved all spending, staff entitlements for meal breaks and overtime were typically denied in district health boards.
''And when those entitlements are not approved, the result is short-staffed wards and the potential for compromised patient care. For everyone's safety, ward and unit managers must be allowed to approve spending when it is needed.
''We want the Minister of Health to top up Southern DHB's coffers and make sure there is enough money for capital investment, maintenance and safe staffing levels that allow the nursing team to provide high quality care to every patient, every shift, every day,'' Ms Harry said.
The board has said two senior executives would focus solely on cost reduction, and the areas targeted for cuts are travel, staff recruitment, and spending delegation levels.
Chief executive Carole Heatly has said she will also pay more attention to the finances.
A spokesman for Ms Heatly said she was not approving all spending, but would lead the ''overall process'' to reduce cuts.
