The Anglican Church is disputing the safety of a plan put forward by a group wanting to restore the cathedral.
The Great Christchurch Buildings Trust announced on Tuesday that the cathedral could be restored for $67 million, as opposed to the $220 million the church says is needed.
One of the most contentious factors in the $153 million difference is whether base isolators - flexible bearings in the foundations to minimise damage during an earthquake - would be needed.
The proposal by the trust excludes them.
However, Anglican church spokesperson Rev Jayson Rhodes said base isolation would be needed for the building to withstand future earthquakes.
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