The Minister for Finance has said that Ireland will have less influence in Europe if the Lisbon Treaty is rejected.
Brian Lenihan was attacking the claims of the 'No' campaigners who say that Ireland will lose out by the loss of a commissioner and changes to the manner in which decisions are made.
Today's Red C poll in the Sunday Business Post shows support for a 'No' vote at 39% - up six points, but the 'Yes' campaign remains ahead on 42%.
"In relation to the Council, the entire voting procedure is being changed so that when there is a majority vote it has to be a majority in population and in number," Minister Lenihan said, "The small member states have a veto. It's a changed voting system."
But Sinn Fein has repeated its claim that Ireland will have less influence on important European decisions if the Lisbon Treaty is passed.
Sinn Fein MEP Mary-Lou McDonald has claimed that changes, such as the loss of a commissioner and the different voting system, will favour large countries.
"The fact is that as things stand, you need a majority of states for a decision to be taken. What Lisbon does is it changes the voting system to favour the countries with larger populations," Ms McDonald said.