Minister for Finance Michael Noonan has said there is a "moral pressure" on banks to cut their mortgage interest rates if they cannot justify them.
Mr Noonan said banks should not be charging so much to customers when they are able to borrow money so cheaply themselves.
The Minister is meeting the Governor of the Central Bank this afternoon to discuss the issue.
He said he could not force banks to change their rates, but that there was a "moral pressure" for them to do so.
"I would like the Central Bank to compare the variable mortgage interest rate to the cost of money in the market at the moment - there seems to be quite a wide gap," he said.
"I would like then the banks to justify that gap once the bank has produced the under-pinning data.
"It's in that space I would like to exert the moral pressure."