Government action to reduce the price of petrol and diesel came into effect at midnight.
The Dail last night voted to reduce the rate of excise charged on petrol and diesel by 20 cent per litre on petrol, 15 cent per litre on diesel and 2 cent per litre on green diesel used for agricultural purposes.
The reduction will be in place until 31 August and will cost €320m.
Some fuel stations have been accused of price gouging.
Many organisations representing motorists and the transport sector say the cut in excise is not sufficient.
Coach tourism and transport operators said the viability of the sectors is now under direct threat.
Agricultural contractors say the reduction is totally inadequate.
The government says as a buyer Ireland has little option but to be a price taker and the current situation is a consequence of the uncertainty and limits on supplies due to the war in Ukraine.
An Taoiseach Micheal Martin is to attend an informal summit of the European Council in Versailles France today with Russia’s invasion of Ukraine set to be at the top of the agenda.