Anglican Bishop Victoria Matthews announced plans to deconstruct the cathedral to a safe level of 2-3 metres above the ground earlier this year.
The decision sparked public protests and the GCBT, led by former MP Jim Anderton, battled to save the landmark city centre building.
They sought a declaratory court judgment to determine whether the Anglican Diocese of Christchurch's decision to deconstruct breached an Act of Parliament designed to protect church buildings.
Today Justice Chisholm agreed the historic building's custodians were acting outside the Church Properties Trust Act 2003 when they decided to deconstruct earlier this year.
He granted an application for judicial review which meant demolition work must be halted.
No timeframe was given for the review, but Justice Lester stressed it should happen "as soon as possible".
He ruled that the church's trust requires there to be a cathedral building on its exact Cathedral Square site.
But he further stated that the building does "not necessarily have to replicate the cathedral as it stood before the earthquake".
"After giving the matter considerable thought I have concluded that the court should intervene and that it would be inappropriate to refuse relief altogether," the judge writes in his 200-paragraph decision.
He said he was influenced by seven matters.
Given the "intense and legitimate" public interest, he said the court would be falling short in its duty if it failed to ensure that the decision-making process was properly completed.
He said the CPT, while having to make a difficult and complex decision under tight time pressures, was wrong to think its cathedral trust was there only for the advancement of religion and maintenance of the ecclesiastical institution, not particular buildings.
There was a "misunderstanding" within the church over how it could spend its insurance money and he raised concerns over "informal" intentions by the church over rebuilding on the cathedral site.
"An informal intention can be overtaken by events," he said.
"It is also possible that the project will lose impetus once the transitional (cardboard) cathedral has been built."
The High Court hearing, held in Christchurch on October 3 and 4, had also "exposed contestable issues" about engineering, cost, and other aspects that were not before the CPT when it made its decision to deconstruct.
The CPT can now consider the new information, Justice Chisholm said.
In summing up, he said: "In my view these matters provide a compelling case for the court to intervene and grant relief."
Bishop Matthews says the church would consider the decision.
"We are pleased the decision to deconstruct the old cathedral and rebuild a new cathedral was confirmed by the judge," she said in a statement on behalf of CPT.
"As we have said since March the new design will be a mixture of old and new and it will be beautiful."
