More than 18,600 people are calling for the Christchurch City Council to reverse its plan to spend an extra $15m on the city's iconic cathedral.

The council agreed in May to contribute the additional money from its $44m surplus towards Christ Church Cathedral's rebuild, as long as central government and the Anglican Church do the same.

The rebuild of the earthquake-damaged building has been on hold since 2024 because of a $45m funding shortfall.

The council money depends on the government also contributing at least $15m and the church showing it can complete the project, after its budget was revised to $219m when costs blew out to $248m.

A petition by local James Pawson is calling for the city council's decision to be revoked and this year's 7.35 percent rates rise to be revisited.

"The restoration of the cathedral is indeed an important cultural and historical project yet it raises critical questions around funding priorities and equity, especially in an economic climate where many residents are already facing financial hardships," the petition said.

"The decision to allocate $15 million of ratepayer money to a project that should arguably be funded by the Anglican Church sends the wrong message to the people of Christchurch who are directly affected by this rates increase."

On Wednesday morning the petition had received 18,650 signatures.

The Christchurch City Council said it would not comment as it had not formally received the petition.

Christ Church Cathedral Reinstatement Ltd chair Steve Wakefield said a range of views existed regarding the cathedral's future including strong support for restoration.

"A common theme is that [Cathedral] Square cannot be revitalised without the cathedral being reopened. The council has considered community input and made its decision, which is contingent on central government support for the reinstatement, and we are all working toward that outcome," he said.

Only 14 percent of submitters supported further funding for the cathedral during annual plan consultation.

The city council has already committed $10m to the project via a ratepayer levy.

In May, 12 councillors voted in favour of the extra $15m of support. Two abstained and three councillors - Celeste Donovan, Yani Johanson and Andrei Moore - voted against it.

At that meeting, Cr Moore accused other councillors of ignoring public feedback.

"Fourteen percent of the respondents supported funding the cathedral and our response to that has been not only to fund $15 million to the cathedral but also to expedite that to the annual plan rather than the long-term plan that we asked them about in the first place, which will leave many wondering what the point was in having their say in the first place," he said.

The council also voted to support two other projects - $15m for upgrading and quake-strengthening Canterbury Museum, and $4m for the Christchurch School of Music.

Both grants were also conditional on other funding being found to complete the projects.