Earthquake insurer Southern Response is appealing a High Court decision allowing a class-action lawsuit by policy holders.
About 40 policy holders want to sue the Government-owned body, claiming misrepresented policies, undue delays in processing and the understatement of build costs after the 2011 Christchurch earthquake.
Southern Response is the company responsible for settling insurance claims by AMI policy holders, after AMI's sale to IAG in 2014.
Justice Gendall approved the lawsuit in the High Court last December.
Southern Response today announced it had filed an appeal against the decision.
The lawyer representing the plaintiffs, Grant Cameron, said the move was a disingenuous, cynical, delaying tactic.