Future spending on Wellington's ageing pipes and plans to fund disaster recovery could be at risk after city councillors overturned a previous decision to sell its airport shares.

Councillors yesterday voted nine to seven in favour of stopping the move to sell the council's 34% stake in Wellington International Airport, valued at $492 million.

A Notice of Motion was brought by a councillor to amend its 10-year Long-term Plan with the aim being for it not to proceed with the sale.

Wellington Mayor Tory Whanau admitted to 1News the process "could have been handled better and individuals could have handled this better — that includes myself".

The council's 2024-2034 Long-term Plan, adopted in late June, called for the profits from the airport shares sale to be invested to help cover the cost of the city's $2.6 billion insurance shortfall in a major earthquake.

Council staff said $400-600m will need to be cut from the budget.

"We'll be looking at our capital programme overall, and that includes things like the pipes, transport, social housing, and possibly our service levels," Whanau said.

Councillors must also work to repair their damaged relationship with Māori.

The vote went against a precedent where iwi representatives have a say on long-term plan decisions.

"They didn't accept the process in which this occurred and there has been some mamae (hurt) created as a result of that," Whanau said.

Another Long-term Plan process will now get underway.