The Secretary General of the European Commission has warned Irish voters of the consequences another rejection of the Nice Treaty.
He said Ireland would run the risk of losing out on the advantages an enlarged single market and was critical of the racist undertones in some of the comments made by elements of the No camp.
Addressing a breakfast hosted by the Dublin Chamber of Commerce, Mr David O'Sullivan said the single market would be enlarged by 100 million people and would "boost economic growth and create jobs providing more opportunities for business to exploit the potential of a huge open market".
Mr O'Sullivan said he abhorred the racist undertones that accompanied the discussion of immigration and said immigration "was a positive source of dynamism and skills renewal. Countries benefit from being open to immigrants".
Speaking after the breakfast, a spokesperson for Dublin Chamber, Mr Jerry Minihane, said: "Dublin Chamber is always balanced in its approach to referendums and elections of any sort but the case for a Yes vote is overwhelming.
"Nice is necessary for enlargement, there is no debate on that point. People need to realise how crucial Ireland's ratification of the treaty is and the very real dangers that exist if the treaty is defeated".
