Ireland is staring down the barrel of fines of 25,000 euro a day for not adopting strict European rules on renewable energy.
The Government has been warned that it should have climate change targets in law for achieving a fifth of power from green resources by 2020.
Ireland joins Austria, Poland and Cyprus in facing severe financial penalties for not transposing the directive last month.
Energy Commissioner Gunther Oettinger said the final bill for fines would be decided by the Court of Justice of the European Union.
"It is essential that all the Member States implement the renewable energy legislation. Renewables are vital for the security of supply and European economic growth. They are key in mitigating global climate change," he said.
The European Commission has proposed a daily penalty of 25,447 euros (£21,000) based on what it says is the duration and the gravity of the infringement.
The Government was twice warned over the danger of fines after only adopting some aspects of the Renewable Energy Directive including a letter of formal notice in January 2011 and a reasoned opinion in June 2012.
The Commission said a considerable amount of legislation required by the directive has been adopted but priority targets of 10% for renewables in transport, streamlined administration and man agement of grid access for electricity from renewables.
It also set out sustainability criteria for biofuels and bioliquids which includes that they cannot be produced from areas which are protected, which store large amounts of carbons like forests and bogs or which have high biodiversity value.
The directive was part of targets to curb climate change by having one fifth of final energy consumption from green sources and to cut greenhouse gas emissions by a fifth compared to 1990 levels.
Earlier this week the Commission announced a series of proposals for bigger environmental targets up to 2030, including a target to cut greenhouse gas emissions across the European Union by 40% on 1990 levels.
It also set out proposals for a EU-wide binding target to meet 27% of energy consumption from renewables by 2030.
The Department of Communications, Energy and Natural Resources said the issue over the directive was technical.
"Ireland complies fully with all the obligations imposed by the Renewable Energy Directive, and the EU Commission does not dispute this fact," a spokeswoman said.
"We have already transposed the bulk of the directive and we are committed to having the remaining technical provisions fully transposed as early as possible in 2014 - and, in any event, well in advance of any hearing in the European Court."