Taxpayers would pay most of the cost of repairing future earthquake damage to uninsured Christchurch infrastructure, a spokesman for Finance Minister Bill English says.

Insurer Civic Assurance has told the Waimakariri and Christchurch councils their earthquake cover won't be renewed after June 30.

That would leave them liable for future damage to assets including AMI Stadium, the Town Hall, the convention centre, all council buildings and even underground infrastructure.

In Christchurch's case, the above-ground assets it owns are worth $1.85 billion.

A spokesman for Finance Minister Bill English this afternoon said Government and Christchurch ratepayers would split the cost of repairing future earthquake damage to essential infrastructure left uninsured on Friday.

Government was liable for at least 60 per cent of that bill under the Civil Defence and Emergency Management Act, he said.

"In regard to Christchurch and Waimakiriri, if there is further damage to essential infrastructure it will be repaired - it is just a question of where the balance of costs fall between ratepayers and taxpayers.

"But we've said we'll be mindful of Christchurch's reduced ability to pay. They certainly wouldn't be expected to foot the bill themselves."

Government was working with insurance companies, the Earthquake Commission and local government to find a permanent solution to the insurance issues, he said.

Civic Assurance chief executive Tim Sole this morning told Radio New Zealand reinsurers had been " very badly burned" by the Christchurch earthquakes, leading many to pull out of New Zealand altogether.

His company had paid $7.5 milion in reinsurance premiums last year, while the full insured cost of the quakes was now around $750 million, he said.

"We can only renew our policies if we know we can pay out claims. We cannot get reinsurance."

It was unlikely Christchurch City Council or Waimakariri District Council would be able to turn elsewhere for earthquake insurance, he said.

"They would struggle deeply to get cover and they could have to turn to Government to provide that cover."

Christchurch City Council's general manager corporate services, Paul Anderson, said the council was not sure what it would do.

"We're working with our brokers to continue to try and place insurance. It's a huge battle."

It wasn't sure at this stage whether it would be able to get insurance even if earthquake cover was excluded.

Waimakariri District Council wrote to the Government about the issue on Friday.

Manager of finance and business support, Jeff Millward said: "Our brokers have said we're 99.9 per cent sure to get insurance, but not for earthquakes."

That included anything to do with earthquakes, such as fire, tsunamis and volcanic eruptions.

"Therefore we have no option but to put a proposal to the Government and ask for some sort of cover until confidence is restored back into the market.

"At the end of the day, what do you do?"