"Government by the cruel," he said in a social media post supporting the Dunedin City Council’s Save Our Southern Hospital campaign.
Sir Sam, of Central Otago, said he was not surprised Prime Minister Christopher Luxon "and his gang have broken their word and made fatal cuts to our Dunedin hospital".
Angry was the way to feel about this, he said.
The Dunedin City Council voted unanimously yesterday to approve an authorised overspend of $146,099 on the campaign.
This included about $37,000 relating to a large public march in Dunedin last month and more than $52,000 for marketing and publicity.
Strength of public feeling was one consistent theme raised at yesterday’s council meeting.
Keeping the government accountable amid broken promises was another.
"Our community is totally behind us on this," Cr Christine Garey said.
Cr Carmen Houlahan said she was there when Mr Luxon "looked us in the eye" and made pre-election promises.
"The public are fully behind this campaign," she said.
The government announced a project revision last month and asked officials to look urgently into options for either a scaled-back design or a retrofit at the old site.
Mr Luxon, who is to visit Dunedin today, has said the city would still get a "great" hospital.
Cr Steve Walker said the southern region needed a better facility than a "slightly patronising, unworkable piece of nonsense".
Cr Brent Weatherall said he felt southern voices were being heard.
"We cannot and will not take a second-best option for the health and wellbeing of the southern region," he said.
Deputy mayor Cherry Lucas said an estimated 35,000 people at the march had been clear the city should not take the government’s decision lying down.
She suggested money for a proposed Waikato medical school could be better spent in Dunedin.
Cr Lee Vandervis said the campaign had been successful so far, but he cautioned the council against getting involved in any drawn-out campaign.
He did not believe "government bashing" would help the city get what it needed.
The government had to deal with "a legacy issue" and find a viable way forward, he said.
Cr Marie Laufiso disputed suggestions the council was getting into territory that was not its business.
"It is already a health system that does not serve our people well — and we have to fight, we have to fight for everybody."
Dunedin Mayor Jules Radich said the government still had time to build the hospital that was promised.
"That promise is not broken yet," he said.
"It makes no sense to nickel-and-dime the capital cost of the hospital."
This would lead to operational inefficiency, he said.
Cr Kevin Gilbert said the government had an opportunity to save face.
"I believe that it is possible for the government to deliver its promise and still retain at least a modicum of respect."
The council plans to reassess the direction of the campaign after a decision from the government, or after receiving more information, about December 10.