Phoenix Gas increased prices by an average of 10.8% last October

The company's announcement last Friday of the increase due on 1 April met with widespread anger.

Last October, the company was widely criticised for a rise of almost 11% in bills for domestic and small business customers in Northern Ireland.

Eleanor Gill, chief executive of the Consumer Council, said on Tuesday that they were disturbed at the extent of this latest price rise.

She said consumers needed to be given confidence to sign up for gas both now and in the future.

"Gas price increases must be open, transparent and reasonable," she said.

"It is the council's view that Phoenix's two recent price increases have raised serious questions, which have not been answered satisfactorily.

It is our view that Phoenix's 20% demand is an excessive rather than a prudent one - this needs to be reassessed Eleanor Gill General Consumer Council

"The latest announced 20% price increase must be delayed until critical queries are properly and openly addressed."

One of the council's major concerns is that consumers were being asked to foot a bill which Phoenix had not yet received from its gas supplier Centrica.

She said: "Is it the role of consumers to act as credit agents for Phoenix?"

Ms Gill said consumers must not face "unreasonable price demands" from Phoenix while efforts were being taken to ensure the best possible terms from their supplier.

"It is our view that Phoenix's 20% demand is an excessive rather than a prudent one - this needs to be reassessed."

Phoenix and Centrica have been involved in an argument over the proposed rise in price for months and court proceedings are currently under way.

Ms Gill said last October's increase of 10.8% included 5% aimed at covering the wholesale gas cost increase.

The situation remains urgent and we require action to be taken Sir Reg Empey Former enterprise minister

"Now it is asking consumers to pay a further 20%. Consumers need to be assured that they are not being asked to pay for the same gas twice," she said.

She said only domestic and small commercial users were being asked to pay the rise, and expressed concern that big business was being subsidised by small customers.

Former Stormont enterprise minister Sir Reg Empey has met Phoenix to discuss its price rise.

The Ulster Unionist MLA said on Tuesday that Phoenix had to take some responsibility for the second increase in six months.

"While I fully accept that Phoenix Gas are not solely to blame because their supplier that has put up their wholesale price, the situation remains urgent and we require action to be taken," he said.

Meanwhile, a report published on Tuesday has warned that the rural west of Northern Ireland would suffer if natural gas was not extended to the region.

Gas to the West, commissioned by a group led by Strabane District Council, suggested a quarter of the province's population could suffer an economic, environmental and social crisis unless immediate action was taken.

One of the report's main aims is to get the rural west included in an imminent government feasibility study.

Feasibility study

Philip Faithfull, chief executive of Strabane Council, said: "A feasibility study by DETI and the Department of Communications, Marine and Natural Resources, will look at running a natural gas pipeline from Derry to Letterkenny.

"While we are adamant that the pipeline should extend to Strabane as a gateway into the rural west, there are currently no definite plans to include the area."

He said the group wanted their consumers and businesses to experience the same positive impact of natural gas as those in the Greater Belfast area had witnessed on industrial development and the environment.

"Excluding the rural west from plans to extend it across Northern Ireland could alienate the region even further, threaten industrial development and weaken chances of future regeneration," said Mr Faithfull.

Sinn Fein MP for West Tyrone Pat Doherty said the report presented "a compelling economic, social and environmental case" for the extension of natural gas provision.