Mr Clark, 72, is in Dunedin Hospital following a minor heart attack on Wednesday afternoon.
Mr Clark was admitted to Southland Hospital and stayed overnight as a precaution. On Thursday morning he was transferred to Dunedin Hospital for further tests.
Deputy mayor Tom Campbell said Mr Clark was scheduled to undergo quadruple bypass heart surgery next Wednesday and would remain in Dunedin Hospital with his family until then.
"I have spoken to Nobby today and he remains positive and is really champing at the bit to get it over with and back on the road to recovery," Cr Campbell said yesterday.
Mr Clark’s recovery was likely to take a couple of months and he would take the reins at council until such time the mayor was ready and able to return, Cr Campbell said.
"As we move into the new year, I look forward to making sure there is no loss of momentum on the projects Nobby has been driving."
Mr Clark and his family continued to request privacy while they focused on his recovery, but were grateful for the messages of support, Cr Campbell said.
Quadruple bypass heart surgery is performed when four blood vessels that feed the heart are blocked.
The surgery is needed to reroute blood around the blockages with vessels taken from other parts of the body.
Cr Campbell described Mr Clark as being OK and "pretty chipper".
"He is a bit shaken but that is what you would expect when this happens to anyone," Cr Campbell said.
"As a guy he is very resilient and is as tough as old boots. He is in good spirits."
The physical recovery would take about two months but he suspected Mr Clark’s family might have to tie him to the bed to stop him being involved in council business, Cr Campbell said.
"I would be really surprised if Nobby is not getting involved during those two months, even if it is by Zoom."
He would be filling the mayoral shoes for the next two months and the council would continue to go about its business, Cr Campbell said.
The main item of business for the council was to work through the long-term plan and try to have it finalised by some time in February.
There was also a rates increase to be decided by the end of February and Mr Clark would no doubt want to be involved in that, he said.
"We will carry on carrying on."
Cr Campbell, 72, was voted on to the council at the last election in 2022. He was the second-highest-polling candidate behind Nigel Skelt.
Hailing from Glasgow, Cr Campbell came to New Zealand in 1981 to manage the Tiwai Point smelter. He then worked in Montreal, Canada for Rio Tinto.
He returned to Invercargill, with grandchildren still in the town, and has remained.
In that time he has been chairman of the Energy Efficiency and Conservation Authority (EECA) and the NZ Institute of Geological and Nuclear Science.
