A group trying to save the ChristChurch Cathedral is warning the Canterbury Earthquake Recovery Authority it will also face litigation if the demolition goes ahead.
The Great Christchurch Building Trust is arguing at the High Court in Christchurch that the significant national and international interest in the cathedral's future means it should be subject to judicial review.
It is seeking a declaratory judgement to prevent the Anglican Church from carrying out plans to demolish most of the heritage building badly damaged in the February 2011 earthquake.
The trust's lawyer, Francis Cooke, QC, told the court on Wednesday the Anglican Church's decision is in breach of its obligations under the Church Properties Trust Act to maintain and repair the cathedral.
Mr Cooke outlined what he called significant amounts of community money that has been put into the cathedral to build and maintain it since it was commissioned in 1858.
He told Justice Chisholm on Wednesday that church trustees cannot be free to do with it what they like and have obligations to protect it for the community.
The trust argues that the civic services of the cathedral are just as important as its ecclesiastical services and, as a Church of England, it is the church of the nation.
Mr Cooke said if the Canterbury Earthquake Recovery Authority was to enter into a demolition contract, it would have to consider its legal obligations to the treatment of such a significant building.
The Anglican Church's lawyer, Jared Ormsby, told the court there is no money to save or restore the cathedral.
Mr Ormsby said the five years it would take to construct a replica would cost $109 million and if the Church waited 10 years to raise the money the cost would be $187 million.
He said the building needs to be deconstructed to make it safe in accordance with the notice from the authority.
The Anglican Church's announcement in March this year that the cathedral would be brought down to a level of of two metres prompted protests in the South Island city.
Those fighting for it to be rebuilt say they have already been offered at least $14 million in donations.