SIPTU has called on Minister for Finance Michael Noonan to withdraw the 9% VAT rate from the hospitality sector unless employers agree to take part in a Joint Labour Committee (JLC) to regulate wages and conditions.
The union claims employers have refused to pass on the real financial benefit of the cut to customers, employees or the Exchequer.
However, the Restaurants Association of Ireland has accused SIPTU of targeting the most successful job creation measure.
The JLC wage-setting mechanisms were struck down by the Supreme Court in 2011, but new legislation has been passed to restore the sectoral wage deals to protect hundreds of thousands of low-paid workers.
SIPTU said hospitality employers have refused to negotiate a new JLC for the sector.
The union said employers have benefited from the 2011 cut in VAT from 13.5% to 9%, which was intended to stimulate employment.
SIPTU claims research shows that employers have not passed on the benefits of that cut.
It said employers driving down wages and conditions have fuelled a shortage of skilled staff, and that many of the new jobs in the sector are part-time.
The Restaurants Association of Ireland rejected SIPTU's claims.
RAI Chief Executive Adrian Cummins said the previous hospitality JLC had been unworkable and that SIPTU was attacking a highly successful job creation measure.
