Sinn Féin has called on Irish MEPs to back a resolution which would effectively put the deal on hold pending a legal review by EU judges.

More than 145 MEPs have declared their support for the resolution, though this remains well short of a majority in the 720-seat parliament.

The controversial EU-Mercosur trade deal will create the world’s biggest free trade zone with a combined population of over 700 million people.

Most EU countries are in favour of the deal, though Ireland is among countries which have opposed it, largely due to concerns from Irish farmers about beef imports.

Sinn Féin MEP Lynn Boylan said: “All Irish MEPs should support this crucial resolution to test the legality of the Mercosur agreement.

“There are serious concerns regarding the compatibility of Mercosur with EU climate and environmental law and that any future legislation on sustainability could be undermined by the provisions allowing Mercosur countries to get compensated for trade effects of EU sustainability policies.

“I am proud to have been involved in the drafting and tabling of this crucial resolution and believe that it can demonstrate why ratifying Mercosur will be so disastrous for our environment.”

Fellow Sinn Féin MEP Kathleen Funchion said: “We know this deal is bad for farmers, public health, and the environment, but it also undermines the democratic processes in the EU and could set a dangerous precedent of the EU Commission overreaching and pushing through policy against the normal order and procedure.

“We will be voting to refer the Mercosur trade deal to the Court of Justice of the European Union next week, and I would encourage all Irish MEPs to follow suit, in the interests of Irish farming and public health.”