The Government should cap the cost of energy, rather than hand out new electricity credits.
That's according to People Before Profit TD Paul Murphy, who said the electricity companies are 'free to pocket' the €200 credits.
Ministers are said to be considering a further credit as other supports taper down in March.
A number of these, including reduced VAT and excise on fuel, are due to stop at the end of February.
Deputy Murphy told The Pat Kenny Show the Government needs to make a much bigger intervention.
"I think people will be happy to have something," he said.
"Clearly something is better than nothing, but it is entirely inadequate.
"The cost of living crisis has, I think, gone away for the moment from the headlines... but it's still dominating people's lives."
He said there is a structural problem with these energy credits.
"People are really suffering this winter - 40% of households are now in energy poverty, which means they're spending more than 10% of their total household income on energy," he said.
"People are in a crisis situation, so clearly people will welcome a €200 credit.
"There is a structural problem in how the Government is doing this, which is that there is no price controls being put on the electricity companies.
"The electricity companies are free to pocket this €200, or a large portion of this €200, by simply keeping prices artificially high.
"The crucial factor that is driving the cost of living prices - both in terms of food and in terms of energy - is profiteering by these corporations".
'Renationalise the energy sector'
Deputy Murphy said the ESB should also be run on a non-profit basis to reduce energy costs.
"I think we need to renationalise the energy sector," he said.
"We need to reintegrate the ESB Group - which is publicly owned - but is run currently on a for-profit basis, and where it can't cross-subsidise from its generation sector into its supply sector.
"So they're legally not allowed to say 'We're making these huge profits over here, we're going to keep our prices low'.
"Then we need to have set price controls.
"The Government has the power to say: the maximum unit price of electricity you can charge is 25c.
"Let's make electricity actually affordable to people, people need it to live".
'It hasn't worked'
Deputy Murphy said the system has to change going forward.
"The market is separated into suppliers and generators; the big profits are not being made at the supply side," he said.
"They're being made at the generation side - in particular biorenewables - but because the market is set up in this way, you get big profits over here but then massive prices for ordinary people.
"We have to reject that logic of saying that we're going to run our electricity on a for-profit basis," he said.
"It hasn't worked in terms of climate, it hasn't worked in terms of providing low-cost electricity.
"Instead we need to renationalise the energy sector as a whole and say we're going to run it as a public utility.
"The ESB, when it was the State monopoly, was extraordinarily successful," he added.