The Employment Wage Subsidy Scheme (EWSS) is being cut by up to €147 a week for each staff member today.
Until now, the state paid up to €350 a week towards a worker's wages.
But from today, the maximum rate is €203.
Padraig Cribben, the chief executive of the Vintners Federation of Ireland, is calling on the Government to reverse the decision.
Mr Cribben told Newstalk: "What we have seen over the last two weeks is a very, very significant amount of the parties that would take place at this time of the year being cancelled on foot of the public health advice."
He added: "Yes, it is necessary that the supports be maintained at their current level until those restrictions are lifted."