THE European Commission is to impose a "quasi-permanent" monitoring programme on Greek public finances, using new powers under the Lisbon Treaty.
The Greek government will need to provide a detailed list of measures and a timescale for their implementation to Brussels.
Greece's deficit is more than four times higher than eurozone rules allow.
Earlier, the Commission approved Greece's plans to reduce its budget deficit, but is worried about the country's unreliable economic statistics.
Athens has been told to cut its deficit of 12.7pc last year to below the EU limit of 3pc by 2012.
Economics Commissioner Joachim Almunia said the Greek government will have to report on the implementation of its budget measures every three months.
If the other EU states and the Commission are not satisfied with the performance they can insist on additional new measures being taken.
The European Commission has the power to impose budget measures on a government as detailed in the Lisbon Treaty.
"It is the first time that the budgetary and economic surveillance instruments foreseen in the treaty are used simultaneously and in an integrated way," Mr Almunia said.
Meanwhile, the Commission is seeking a change in EU law to give the European statistical agency Eurostat the right to audit national statistical agencies.