A number of former employees staged an overnight protest at Co-operative Poultry Products, a Co Cavan poultry-processing factory which announced yesterday it was closing.
The protest centres on redundancy payments for many of the 90 people who lost their jobs with the closure of the Cootehill company.
Workers were informed yesterday evening that the plant was to close immediately.
The company had tried and failed to sell the business as a going concern.
In a statement, the company said it was "with great regret that we announce that we are left with no alternative other than to request Bank of Ireland to place our business in receivership".
It said its business had become loss-making, citing substantial feed price rises, rising energy costs, poor market prices until recently, and low quality imports.
All of the factors are presenting a grave risk to many players in the entire poultry industry, it added.
Simon Coyle of Mazars has been appointed as the liquidator for the company.
SIPTU's Jim Finnegan said the closure would have a devastating effect on the local community.
He said: "Not only must 90 workers and their families deal with the loss of their livelihoods but more than 25 local growers have also lost their source of income.
"At a brief discussion yesterday I made clear to the liquidator that SIPTU will be seeking the prompt payment of the workers' redundancy entitlements."