The Minister for the Environment Mr Dempsey has rounded on Sinn Féin and the Green Party because of their opposition to the Treaty of Nice. The Green Party, however has accused the Minister of engaging in mud-slinging and misinformation.
In a statement Mr Dempsey described the Green Party's No vote campaign was "extraordinary" and the Sinn Féin campaign dishonest.
"The Green Party's opposition to the Nice Treaty will be viewed by many as extraordinary", he said.
"One would have thought that the self-appointed guardians of the environment would loudly welcome moves to enlarge the EU so that the countries of the former Eastern Bloc can be helped to radically improve their poor environmental standards.
On Sinn Féin Mr Dempsey continued: "While Sinn Féin's new-found interest in Irish neutrality is commendable, they are wrong when they suggest that the Nice Treaty will introduce changes in this matter.
"Their latest scare tactic is to link the Nice Treaty with NATO membership. This sort of campaign is simply dishonest. The fact is that this Government is fully committed to maintaining Irish military neutrality".
The Greens, however, dismissed Mr Dempsey's attack and called on him to engage in proper debate and not "mud-slinging".
A spokesman told ireland.comthe party was in favour of enlargement and pointed that it could be addressed outside the context of the Nice Treaty.
He added that the Green Party was opposed to the treaty on issues such as militarisation and a two-tier union.
At the launch of the Greens' leaflet campaign last week, Green MEP Ms Patricia McKenna called for the Yes campaigners to concentrate on the substance of the Nice Treaty and, rather than orchestrating a smear campaign against No campaigners.
"The Nice Treaty is primarily about shifting power in the EU from the small states to the big states", she said.
"It automatically increases the voting power of the big States in the EU Council and Parliament, by 2005, even if not a single new Member has joined by then.
"The 'enhanced co-operation' provisions of the Nice Treaty allow the more powerful countries to hijack the EU institutions for their own ends."
