The Irish government expects to take in around 500 million euros (415 million pounds) per year from a new graduated residential property tax, Prime Minister Enda Kenny said on Thursday, three times more than its current flat tax takes in.

The government introduced the 100-euro per property charge at the budget this month and said it expects it to bring in over 160 million euros next year.

Ireland is obliged to increase the residential property tax in 2013 under its bailout agreement with the International Monetary Fund, European Union and European Central Bank.

The government had indicated the new graduated tax replace the flat tax in 2014, but Environment Minister Phil Hogan told the Irish Times on Thursday that it could be introduced in 2013.

If the new property tax brought in 500 million in 2013, it would increase the tax take by 340 million euros, one-third of the government's IMF-EU target to increase tax revenues by 1.1 billion euros that year.

We have introduced a special group to report to the minister by the end of March on the structure of the property tax and how that will be based, Prime Minister Enda Kenny told state broadcaster RTE.

The measure aims to bring in funds of the order of half a billion euros per year, he said, and may be collected directly by local councils rather than the central government.

Several opposition politicians are calling on people to refuse to pay the 100 euro charge on the grounds that it disproportionately hits low income earners.

(Reporting by Conor Humphries; Editing by Toby Chopra)