Sinn Fein has accused the Government of marching Ireland into a European army via the Nice Treaty.
Party spokesman Arthur Morgan rejected the Government's claims that the Seville declaration protects Irish military neutrality and said the document has no legal status.
"The situation is that the Seville declaration and other supposed devices built in are nothing more than smoke and mirrors," he said.
"I think it's a confidence trick on the part of the Government to try and hide over what is a very, very important issue for the Irish people, that of neutrality."