Hundreds of thousands of people in Ireland will struggle to afford increases to heating and fuel prices as a result of carbon tax hikes.
Social Justice Ireland has issued the warning on the back of a report which recommends raising carbon tax from €20 to at least €80 per tonne by 2030.
The body has suggested the move should be made only when a plan is in place to protect those vulnerable to fuel poverty.
Social Justice Ireland CEO, Dr Seán Healy, said this is vital.
Dr Healy said: "It's critically important that there be mitigation in place that there are hundreds of thousands of people at risk of fuel poverty and that their situation is protected in this move.
"The move is very desirable, we need to get action on climate change."
Earlier: Climate Action report recommends rising carbon taxes and electrified public transport
The Joint Committee on Climate Action has published its cross-party report.
It reached an agreement last night on a number of key climate issues and has recommended a series of carbon tax rises up to 2030.
Other recommendations focus heavily on transport with emphasis on electrifiying, improving and extending public transport as well as making it cheaper to use.
While the Irish Farmers Association initially had reservations, the organisation's president, Joe Healy, said it is fair to farmers.
Mr Healy said: "We welcome the fact that they didn't take on board the Citizens' Assembly recommendation to put a carbon tax on food production, because that would have lead to an increase to the price of food for consumers."