Anti-poverty campaigners have branded plans to increase gas prices by up to 40% “frightening”.
It is understood that Phoenix Gas intends to reveal a price hike tomorrow.
Last night the gas firm was staying tight-lipped and refused to answer any questions about the expected rise.
The Consumer Council, which has been in talks with Phoenix Gas, also refused to comment on the price jump.
However, anti-poverty groups say they are shocked by talk of another massive price hike.
Goretti Horgan from the Northern Ireland Anti-Poverty Network said the latest rise in gas prices will heap misery on families already under financial pressure.
She said: “We are lucky we are in the summer months, but people are already frightened about the coming winter months with the increase in the price of oil and gas.
“If this winter is as hard as the last one, people will freeze to death.”
The anti-poverty campaigner believes the new Assembly will have to take radical steps to help people on low incomes.
She said: “The new Assembly will have to look at introducing social tariffs.
“The energy companies all make a lot of money in Northern Ireland every year.
“The Assembly will have to |consider introducing lower fuel prices for people below a certain income. This is all the worse given that oil prices also keep going up.”
If the latest proposed price rise goes ahead this week the cost of the average gas bill will soar to over £600 a year.
It is understood the new tariff will kick in at the start of next month and Phoenix Gas has been in talks with the utility regulator.
Outgoing Assembly Member John Dallat called for an independent investigation into gas and oil price rises.
The SDLP man said: “The most vulnerable people in society are being crucified by these hikes.
“This has to be a priority for the Assembly when it returns because fuel poverty is the major issue facing people in the North, especially when you consider the onslaught on benefits and the various cuts that are being introduced.
“If the Assembly is going to be significant and meaningful for people, then fuel poverty needs to be addressed.”