The Irish government has asked the army to help remove vehicles blocking fuel depots as protests entered a third day.
Haulage and agricultural businesses are angry about the response to rising fuel costs, and have also set up slow-moving convoys on motorways and disrupted major roads in Dublin.
"The blocking of critical national infrastructure will not be permitted to continue and the assistance of the Defence Forces has been requested," justice minister Jim O'Callaghan said in a statement.
He said large vehicles would be removed - and warned owners to "remove them immediately" on Thursday morning, or face the possibility of them being damaged.
Owners "should not complain later about any damage caused to those vehicles during removal", he said.
"Denying people access to fuel and clean water is an unacceptable interference in the most basic of human rights," he added.
Taoiseach Micheal Martin has called the blockading of fuel depots and the Whitegate oil refinery in Co Cork "an act of national sabotage".
He also criticised tractor drivers who snarled up traffic in Dublin and turned the main thoroughfare of O'Connell Street "into a car park".
The city's fire brigade said the protests caused delays getting to emergency calls.
Petrol and diesel costs have soared in recent weeks due to the Iran war and the blocking of supplies through the Strait of Hormuz.
Agriculture minister Martin Heydon said the government would meet with representatives of haulage and farming groups - but would nt engage with the protesters.
He told RTE Radio 1's Morning Ireland programme it was a "clear choice between democracy or anarchy, and we have a rule of law in this country".
"I completely understand where people's frustration is from in terms of (the) very high energy shock as a result of the war that has broken out between America, Israel and Iran," he added.
Ireland's coalition last month approved a €250m (£218m) package of measures to ease the burden.
It included a temporary cut to fuel excise, expansion of a rebate scheme for hauliers and bus operators, and an extension of the fuel allowance.
However, the cuts have been largely eroded by the ongoing situation in the Middle East.
(c) Sky News 2026: Irish army called in to remove fuel depot blockades

Four people die off French coast during attempt to cross English Channel
Man jailed for £2m theft of handbag containing Faberge egg and gold watch
Four arrested as hundreds of suspected stolen phones are found
British man in court for leading fighters in Somalia-based Islamist terror group