Irish MEP Ciaran Mullooly has said that he will raise the decision by Brittany Ferries to end livestock transport services from Ireland with the European Commission.
Mullooly said that he has also written to Taoiseach Micheál Martin on the decision.
According to the Midlands-North-West MEP, there are questions over the implications of this move from the ferry operator for the free movement of goods, as outlined in EU laws on its internal market.
He said Brittany Ferries' decision to withdraw livestock services between Ireland and mainland Europe "has significant implications for the calf trade here and raises important questions about Ireland’s effective access to the EU Single Market".
He said the issue "extends far beyond a commercial decision and has significant implications for Irish livestock exports".
According to Mullooly, Irish livestock producers "comply with all EU animal health and welfare requirements".
"Once those standards are met, they must have a practical means of supplying customers across mainland Europe," he said.
"For an island member state, ferry services are an essential part of accessing the Single Market.
"More than 200,000 Irish calves have been exported to mainland Europe so far this year, and I believe that the loss of a major transport provider could reduce transport capacity, increase costs and weaken Ireland's competitive position," the Independent Ireland MEP added.
Mullooly said he has written to the Taoiseach and to the European Commission to ask "whether this development is consistent with the EU's obligations" under the Treaty of the Functioning of the European Union, particularly the sections of it that deal with the Single Market and the free movement of goods.
"I will also seek clarification on whether adequate maritime transport capacity exists to ensure Irish exporters have effective access to mainland European markets," he said.
"The Single Market cannot exist in theory but fail in practice.
"Ireland's geography means maritime transport is an essential link in accessing European markets," Mullooly said.
"If that access is materially restricted, the commission must examine whether the fundamental principles of the [EU] treaties are are being fully upheld for an island member state," he added.
Mullooly said the matter is "urgent", and that he expects the Taoiseach to "address the matter in the interest of Irish farmers and their entitlements under the Single Market".