Protesters will camp outside 30 meat factories across the country tonight as part of the first nationwide farmer blockade in almost 15 years.
The 24-hour demonstration, which has been organised by the Irish Farmers Association, represents a significant escalation of the beef crisis caused by poor factory prices for beef since last winter.
IFA President Eddie Downey said farmers have had enough and are not prepared to tolerate loss-making prices any longer.
Meat Industry Ireland, which represents the meat factories, says the blockade is misguided and counter-productive.
The IFA is angry over a price gap of €350 per animal that has opened up between what meat factories in Ireland and Britain are paying for cattle.
They say that Britain takes over half of Irish beef exports and they cannot understand how price increases in the UK have not been passed on to Irish farmers who have been making very significant losses on their animals since last winter.
The demonstration will continue until 3pm tomorrow, meaning normal business will be jeopardised at meat factories across the country over the 24 hour period.
The last time a blockade like this happened was in 2000.
On that occasion the courts imposed very significant fines on the IFA over their action.
In a statement this evening IFA President Eddie Downey said: "At their peak today, the protests were attended by over 10,000 farmers who turned out to voice their deep frustration with the factories.
"They have had a very tough year. Our main markets have recovered strongly and farmers are not prepared to tolerate loss making prices any longer."
Mr Downey said farmers are very determined that beef prices at the factories must rise to fairly reflect the very strong increase in UK cattle prices, where Irish beef sales are up 20% this year. Current prices in Britain for R grade steers are running at the equivalent of 4.74/kg incl vat, which is 1/kg higher than the 3.73/kg Irish price.
He called on the meat factories to reflect the improved market situation in beef prices to Irish farmers without any further delay.
In a statement responding to the protests Meat Industry Ireland said IFA actions are "very unnecessary and questionable."
The group said Irish cattle prices have in the past 10 years increased from approximately 92% of the EU average to currently 100% of the EU average.
They added that given that Ireland exports 500,000 tonnes of beef into these EU markets, this is a strong performance.