The Anglican Church has rejected a report which says that ChristChurch Cathedral can be saved.
The Great Christchurch Building Trust last month released a report claiming the building can be restored.
But Bishop Victoria Matthews said the Cathedral Project Group has now considered the report provided by the Great Christchurch Building Trust and dismissed it.
"We have found it is not a safer option. It does not provide any greater protection to the heritage of the building and it is an expensive option," she said.
The Cathedral Project Group said the plan would likely cost $15 million more to strengthen than it would to deconstruct the cathedral.
It also did not provide any greater protection to the heritage of the building, and it does not offer any structural engineering options the diocese has not already considered, the group said.
The group said strengthening would never achieve the same level of functional performance as a rebuilt cathedral.
Quantity surveyors Davis Langdon found the minimum cost proposed by the Trust's report would be more than $100 million if the project was implemented over a seven-year period. If it took 20 years, as Davis Langdon advised, the total cost could be more than $180m.
Matthews said the group does not want to build a replica but rather a mix of old and new.
"We are currently testing design budgets and as soon as we know how much we can spend to build an inspirational building that gives glory to God, we will be releasing that figure. It will be substantially less than $100 million," she said.
Anderton told The Press he was disappointed by the group's findings and would not be giving up the battle.
''Clearly, there's quite a difference the two viewpoints. I don't think it's anything unresolvable,'' Anderton said.