Minister for Communications, Climate Action and the Environment Richard Bruton has said that the Department of Public Expenditure is assuming a carbon tax of €100 per tonne by 2030 in the model it uses for shaping future economic policy.
This is higher than the €80 per tonne suggested by the Climate Change Advisory Council.
It is also five times higher than the tax of €20 per tonne of carbon that applies today.
A carbon tax is a percentage levy applied to motor and heating fuels and well as other carbon intensive goods and energy products.
The more carbon intensive the good or fuel is, the higher the tax, and so the greater is the incentive for people to use less of it.
Currently the carbon tax adds about €2.10 to the cost of a 40kg bag of coal, €0.45 to the cost of a bale of briquettes, and 5.3 cents to a litre of diesel.
If the level of tax assumed by the Department of Public Expenditure and Reform were applied, then the carbon tax would rise to €10.50 on a bag of coal, €2.25 on a bale of briquettes, and to 26.5 cents on a litre of diesel by 2030.
The Government said that it would announce a trajectory for increases in carbon tax out as far as 2030 ahead of the Budget last October. However, in the event it failed to do so.
This is the first suggestion that policymakers may be prepared to go even further in penalising carbon emissions than Climate Change Advisory has so far been seeking.
Mr Bruton was speaking to the press outside Government Buildings to publicise a first draft of Ireland's National Energy and Climate Plan; a new document required to be published under EU law before the end of the year.
Chairperson of the Joint Oireachtas Committee on Climate Change Hildegarde Naughton said she expects her committee will recommend a cross-party agreement on the future of carbon taxes when it publishes its findings at the end of January.
She said that any increase would likely be revenue neutral for the public meaning the proceeds of the tax being paid back to the public in some form.
Mr Bruton said that the draft National Energy and Climate Plan that he published today (and will submit to the European Commission) will be subject to very significant changes before a final version is published by the end of next year.
That final version will be influenced by the outcome of a new "whole of Government approach" to tackling climate change that he is currently championing in Cabinet.
It will also be influenced by the outcome and recommendations of the Joint Oireachtas Committee on Climate Change when it is finished its current examination of the recommendations of the Citizens' Assembly in relation to climate action.
The minister said, the purpose of today's document is to chart a sustainable path for Ireland in a decade when it is projected that the number of households will grow by 380,000 or 19%, and GDP will grow by 30%.
As it stands, the actions included in the draft plan are capable of delivering a cumulative reduction of 22 million tonnes in greenhouse gas emissions.
However, this is just one third of the total emissions reduction that Ireland is required to deliver.
The draft plan also envisages that the use of renewable sources of energy such as wind, solar and biomass in our power system will rise from 30% currently at least 55% and possibly as high as 70%.
In a move that will almost halve the greenhouse gas emissions from electricity, the use of coal and peat for generating electricity in Ireland is to be stopped altogether.
Today's draft energy and climate plan also repeats the Government’s stated aim that electric vehicles will make up 20% of Ireland's transport fleet.
It also envisages that at least 170,000 homes will supported to replace oil-fired boilers with heat pumps and solar panels.
The environmental group Friends of the Earth said today's draft National Energy and Climate Plan is not yet the "revolution" Mr Bruton has promised, but that it welcomes his honesty that this is the case.
Friends of the Earth Director Oisín Coghlan said "the minister has again committed to producing an new all-of-Government Climate Action Plan early in 2019 with additional measures to cut pollution in all sectors of the economy and society, and close Ireland's 'emissions gap'".
He said that "after all the minister's frankness and fine words, the Climate Action Plan he produces in early 2019 will have to be at least as strong as the Citizens' Assembly recommendations, and have as many teeth as the Action Plan for Jobs, to ensure all Departments actually deliver on their commitments".