Nobby Clark said he recently attended and supported Dunedin Mayor Jules Radich in a meeting with Minister of Health Ayesha Verrall to discuss the matter concerning the new hospital.
The hospital will now have fewer beds and operating theatres as part of "design changes".
The Government announced in December the $1.47billion project had completed a "value management exercise" which meant the project now would have 398 beds, 23 fewer than the 421 beds identified in the hospital’s final business case.
Operating theatres have also been cut, from 28 to 26, while the three MRI scanners have been reduced to two and the PET-CT scanner would be installed later
Mr Clark said those changes would not only impact Otago residents but also Southland, as people in the Deep South were "often more reliant on Dunedin Hospital for services than the ideal".
"From my mayoral role, I advised the minister that cutting back on real health needs of our two cities is repeating the Southland Hospital scenario where our hospital was built on poor projections and is now short by two theatres and more than 40 beds, with the emergency department also under too much pressure."
He shared the view of Mr Radich that this blow-out would not be the last in this five-year build timeframe, he said.
"We agree that if we accept changing design and reduce services delivery, [it] can be used every time there is a inflammatory cost on this project [and] we will end up with a less than world-class, future-proofed hospital which supports the whole region.
"This is a slippery slide that I will not be part of as mayor of Invercargill."
He would continue to advocate for what the Government had promised, Mr Clark said.
"Anything less sells short the future health needs of our city.
"Invercargill needs that promised hospital as our back-up facility."
