A decision is expected today about the future of neurological services in the South Island.
The Ministry of Health has been looking at whether all six neurosurgeons will be based in Christchurch, or whether two will be retained in Dunedin.
A public outcry is anticipated if Dunedin's service is axed.
Dunedin neurosurgeon Mike Hunter has been campaigning to keep neurological services in Dunedin rather than moving them all to Christchurch. He says if that happens the likelihood of other health services around the country being centralised is a real possibility.
In August thousands of southerners, including every New Zealand mayor south of the Waitaki River, gathered at the Dunedin Town Hall calling for the retention of the neurosurgery unit at Dunedin Hospital .
The unit currently services 300,000 people and protesters said lives would be lost or patients left brain-damaged if the service was centralised to Christchurch.
The five South Island DHBs had agreed on centralising the region's neurosurgery service but the Canterbury DHB wants all six neurosurgeons in Christchurch, while the southern DHB wants two of the six Dunedin-based.
Figures show 240 patients end up in the Dunedin intensive care unit or on the ward needing acute neurosurgery each year while a further 120 need elective brain surgery. If the proposal goes ahead, nearly all will have to be transferred to Christchurch.
To transport a patient from Invercargill to Dunedin Hospital is a two-hour return trip by helicopter and 80 minutes for a Queenstown or Wanaka pick up. But if patients were to be transferred to Christchurch, that would jump to 3.5 hours from Invercargill and 2.5 hours from Central Otago.
A three-person panel has been reviewing the service and panel head Dr Anne Kolbe said the aim is to deliver safe and high quality care in a sustainable way to all South Islanders.