Sinn Féin has launched its campaign to urge voters to reject the EU constitutional treaty, describing it as "the biggest step so far in the creation of a superstate".
Party president Gerry Adams said yesterday Sinn Féin wanted to see an EU "that promotes sustainable growth, environmental protection, social and economic equality, human rights and global justice".
He believed, however, that the proposed constitution was not in the interests of Irish people.
Mr Adams said Sinn Féin would oppose the constitution in a referendum in the Republic expected next year, and in the North during a UK referendum expected in 2006.
The party's Dublin MEP Mary Lou McDonald said the constitution, if passed, would "transform the EU from a body of co-operating member-states into an embryonic federal state with its own legally-binding constitution.
"It deepens the democratic deficit, further concentrating power in the hands of the few at the expense of national parliaments and ordinary people.
"It undermines neutrality and seeks to transform the EU into a global superpower with its own foreign minister, army and armaments agency.
"It copper-fastens the right-wing economic agenda which has dominated EU policy for over a decade, and seeks to extend such policies to public services and international trade agreements, undermining welfare provision and global justice priorities."
The party yesterday distributed a booklet produced by the European United Left/Nordic Green Left group, the socialist and communist grouping which Sinn Féin is affiliated with in the European Parliament.
The booklet argues the constitution will diminish national sovereignty, move towards a "superstate" and will not reduce the democratic deficit in Europe.
This group is organising a conference in Dublin this month on the constitution.