More than 30 business groups have formed a group to campaign for a yes vote in the up-coming Lisbon referendum.
The vote will take place on October 2.
Members of the new group - called 'Business for Europe' - include the American Chamber of Commerce, IBEC, the Irish Taxation Institute, the Irish Hotels Federation, Chambers Ireland, the Irish Exporters Association and the SFA.
Business for Europe has aligned with Ireland for Europe, the civil society group being led by Pat Cox.
IBEC director general Danny McCoy said: "A yes vote will send a positive signal to foreign investors and to our economic trading partners in the EU. The successful ratification of the treaty is a vital step on the road to Ireland's economic recovery."