Business body Ibec today became the latest group to back the Lisbon Treaty claiming a 'Yes' vote in the upcoming referendum would boost the economy and create jobs.
The organisation, which represents 7,000 employers nationwide, said it would also attract investment and protect the country's business interests.
It comes just days after anti-treaty group Libertas claimed if the document was ratified it would create inequality among EU member states and damage the economy.
"The treaty will ensure that key national interests are protected," said Ibec's Director of EU and International Affairs Brendan Butler. "Our ability to set our own tax policy is guaranteed along with arrangements concerning foreign direct investment.
"This means that Ireland will remain among one of the most attractive places in the world to invest.
"Each previous treaty has created new opportunities for Irish business and has helped create more jobs. This treaty will do the same," he said.
Mr Butler said a yes vote would secure Ireland's place in Europe. In the coming weeks Ibec will launch a major campaign setting out why people should support the treaty.
Taoiseach Bertie Ahern last week announced the Lisbon referendum would be held in the second week of June.
A day later anti-treaty group Libertas unveiled its 'No' campaign and argued a vote in favour of the treaty was a vote against the founding principles of the EU.
It argues that if ratified Ireland's voting power would be weakened while states like France and Germany would be boosted.