Transport Minister Eamon Ryan has admitted plans to cut excise duty paid on petrol and diesel 'won't be enough'.
The Government announced the measure in response to the rising cost of fuel as a result of the Russian invasion of Ukraine.
The plan would see a 15c cut in the price of diesel, a 20c cut in the price of petrol and a 2c cut in the price of green diesel from midnight until the end of August.
However ministers have admitted it will only slow down increased costs.
Minister Ryan told The Hard Shoulder the Government has gone as far as it can.
"I think we should be honest with the public and say 'No, it won't be enough'.
"We are in exceptional circumstances and the level of price increases, it isn't possible and it changes by the day.
"And it keeps changing, so I don't think you could ever do enough.
"But we did need to do something, and Government has done this today - along with the €500m package that we announced three weeks ago to help householders on their electricity bills, and a long with measures done in last October's budget.
"This is a crisis that has been slowly evolving in terms of higher energy prices, but which took off in the last two weeks because of the invasion of Ukraine.
"We just have to be clear and honest: we can't fully protect against all the consequences of that.
"But we went to the max of what we could do within European law, and doing it in a way that was designed to be quick".
Minister Ryan says the Government will be looking at more measures over the next few weeks.
"We'll be coming back in a number of weeks' time, particularly looking at a number of efficiency or other measures that can help people save money in other ways.
"We're going to have to continue to respond in an increasingly flexible way.
"I think the focus will switch towards efficiency, because the international prices are outside our control".
And he says more will have to be done to help those operating in the school transport and haulage sectors.
"I think it's really important that the haulage industry which is badly affected, badly exposed... where they're tied into a contract, or where their customers are not allowing them pass on the cost, that is one of the areas we will have to look [at].
"In those sort of areas where a public service can't be provided because that long-term contract is not reflecting some of the prices, we will in certain targeted areas have to adjust and amend".