Fianna Fáil's demanding the coalition put pressure on banks to stop "gouging" money from variable rate mortgage holders.
The party is putting forward a Dáil motion tonight calling for Government action on what it says is costing homeowners between €1,000 and €6,000 a year.
Finance Spokesman Michael McGrath said existing variable rate customers are being hit in a disproportionate way.
"The Government has gotten away with doing absolutely nothing about this – they haven't met the banks officially for over three years."
"At a time when people on variable rate mortgages are being gouged in this way by the institutions, it simply does not stand up."
"We know for a fact that the cost of funds for the banks is between 1-2% … yet they continue to charge between 4 – 4.5%"