Bord Gais is circulating "inaccurate and misleading" fuel cost comparisons to the public, according to an association representing the petroleum industry.
OFTEC (the Oil Firing Technical Association for the Petroleum Industry) has also accused the gas supplier of employing "dirty tactics" to persuade the public to switch to natural gas and challenged it to justify the running costs quoted in its current "scrap now and save" advertisement campaign.
The association has also challenged Bord Gais to justify their claim that natural gas is Ireland's most economical fuel for home heating.
"The £1 per day quoted by Bord Gais for heating an `average home' is completely misleading," said Mr Duncan Pollack, OFTEC's marketing director.
He said figures published by analysts Sutherland Associates show that in May a family's heating and hot water bill for an average three-bedroom home using natural gas was £610 a year. "This is much more than £1 a day. Even if water heating is excluded, the space heating cost would still be about £1.33 per day."
He said the annual cost for heating and hot water for a similar home using oil would be £564, a saving of £46. He said prices have fallen since May, that world oil prices are at a record low level and that this looks set to continue.
