Groups representing consumers and older people say that a further hike in gas prices will cause more hardship if approved.
The warning comes as the Commission for Energy Regulation (CER) announced it has begun consulting on a submission received from Bord Gáis Energy.
The company is requesting an increase of over 7% in residential gas tariffs from this October.
If approved experts say it would push the average annual domestic gas bill above €1,000 for the first time.
Age Action Ireland said that if gas prices rise by a further 7% it would leave more older people having to choose between food and fuel in the coming months.
Bord Gáis Energy said it recognised that price increases have an impact on customers but maintained it is committed to keeping prices as low as possible.
The CER is expected to make a final decision on the price rise application by the end of August following a public consultation and a detailed review of Bord Gáis Energy's costs.
In a statement, the company confirmed it has applied for a 7.22% increase in residential gas tariffs from 1 October 2013.
It said the main driver for the proposed increase is the rise in transmission costs which it said are expected to increase by up to 38% from 31 October.
The company added that other factors affecting the tariff include continuing upwards pressure on future wholesale gas prices and increases in supply costs.