A 34 per cent rise in gas prices came into force today adding around €25 to the average monthly household bills.
The increase was approved last month by the Commission for Energy Regulation (CER) after Bord Gais complained that the growing cost of gas had added 150 million euro to its costs.
The new price rise applies to domestic and small commercial and industrial users. The latest hike comes on top of a 25 per cent increase exactly a year ago.
The CER said it regretted the unprecedented rise for consumers but said it would promote competition and safeguard supplies in the long term.
Bord Gais described the increase as "hugely regrettable" but added that it was unavoidable due to global market conditions outside the company's control. Wholesale gas prices are expected to stabilise from next year, and price reductions would be passed on to consumers if this happened, the company said.