The State's largest trade union Siptu said today that workers rights would have to be addressed if a new Lisbon vote was to be passed.
Siptu general president Jack O'Connor said that workers had voted against the original treaty, and were unlikely to alter their votes on the new proposition unless issues realting to rights at work were addressed in a "tangible and meaningful way".
"There are issues which need to be dealt with at EU level but a great deal can be done by the Irish Government at an exclusively domestic level," he said.
His concerns were echoed by MEP Proinsias De Rossa, who said the implications of some recent rulings by the European Court of Justice on workers rights needed to be "comprehensively addressed".
"These ECJ rulings were not based on the Lisbon Treaty but on existing European law. European and Irish legislation must be amended in order to address the concerns arising from those judgments," he said.
"The purpose of such amendments must be to ensure that free movement of goods, services, and labour, must not adversely affect labour law and practice in Ireland."
The Laval ruling found that Swedish trade unions could not force a foreign company to observe local pay deals.