Minister for Health James Reilly has criticised plans by Laya Healthcare and GloHealth to increase insurance premiums.
Laya yesterday announced plans to increase premiums by an average of 20%, while GloHealth said its prices would rise by €49 for an adult and €14 for a child.
The minister said the increases were not justified.
Laya's price increases will see a family of two adults and two children pay between €400 and €1000 extra per year in their premiums.
The Vhi has already announced an average increase of 3%.
Mr Reilly commended the Vhi for keeping its increase low, saying the 3% rise was evidence of the success in insisting that the Vhi addresses its own costs.
But he said the increases announced by Laya and GloHealth were disappointing and unjustified.
Mr Reilly urged all insurers to work with Pat McLoughlin, who was appointed by the Government to examine how costs can be reduced in the health insurance industry.
He said a wide range of recommendations have been proposed by Mr McLoughlin, which if implemented would contain costs.
The minister also dismissed claims by some insurers that the decision to charge for all use of public beds by private patients was designed to raise €120m this year.
The figure would be no more than €30m, he said.