The Queen needs more information on how the Christ Church Cathedral could be saved, campaigners say.
Prime Minister John Key met the Queen this week on a trip to Britain. The Queen wanted to speak to him about the Christ Church Cathedral because she has received letters raising concern about its future.
Key said he had taken the Queen through engineering assessments and reports showing why the building could not be saved.
"All I'll be able to do is give her the same reassurance I give Cantabrians, that if we could save the church we would, but on the best advice we've had so far that church can't be saved because of the damage."
Key said he understood the Queen's desire for reassurance "but at the end of the day the Queen isn't an engineer and neither am I, so she won't be able to override the engineering advice we've had".
The Queen is the nominal head of the Anglican Church in Britain, but not New Zealand.
Restore Christchurch Cathedral spokesman Mark Belton said the Queen needed to be made aware that many engineers believe the building can be saved.
"It is really interesting that the Queen has had such considerable correspondence that she made this a priority and has clearly expressed her concern about the restoration," he said.
"John Key seemed to be only taking the advice of the Cera engineers. He is acting on good faith on the advice he has received thus far."
Belton said he would attempt to send the Queen an alternative engineering report on the cathedral that had been commissioned by the Great Christchurch Buildings Trust.
A spokesman for the Anglican diocese said Bishop Victoria Matthews was unavailable for comment.
Matthews is on a world tour of different cathedral sites seeking inspiration for a new cathedral in the Square. The trip was planned to coincide with a trip to Dublin, Ireland, as part of her role with the Inter Anglican Standing Commission on Unity, Faith and Order.