Ireland could be exposed to multi-million euro claims from foreign investors if the EU-Canadian trade deal known as CETA goes ahead, Independent MEP Marian Harkin claims.
She is concerned about the inclusion of a controversial aspect of the trade deal that provides investors with a mechanism to sue states if they are unhappy with certain laws.
The trade agreement was signed by EU leaders and Canadian Prime Minister Justin Trudeau at a summit in Brussels last month.
The deal had been threatened at the final hour as a result of the refusal of the French-speaking Wallonia region in Belgium to pass the deal.
However, Belgian Prime Minister Charles Michel announced a deal which allayed opponents' concerns regarding agricultural exports and the state/corporation dispute settlement system - clearing the way for the official signing of CETA.
Marian Harkin is one of a group of MEPs which is putting a resolution to the European Parliament to refer the CETA deal to the European Court of Justice.
During a debate in the European Parliament last night, Ms Harkin said the Dail must debate the CETA deal.
"I am horrified that Ireland has provisionally signed this deal without a rigorous debate and vote in our Dáil," she said.
"We are the only country in the EU to not have these special investor courts in our legislation - and yet we will leave ourselves open to multi-million claims in our courts if we agree the deal.
"Our Seanad voted to reject CETA - the very least our Dail must do is debate and vote on CETA," she added.