The Minister for Foreign Affairs, Mr Andrews, has called for a strong Yes vote for the Amsterdam Treaty on May 22nd, saying it was "important to our future well-being".
Welcoming the Referendum Commission's plans for a public information campaign, he said much work was needed to bring home to the public the relevance of the treaty.
However, opponents of the treaty last night condemned the decision to hold the vote on the same day as the referendum on constitutional changes necessitated by the Northern Ireland Agreement.
Ms Patricia McKenna MEP of the Green Party also criticised a booklet published yesterday by the commission as posing "leading questions which very much favour the positions of those advocating a Yes vote.
"What is most notable is the absence of any question on the more sensitive aspects of the treaty, such as the moves towards a European federal police force under Europol, or increased majority voting," she said.
The Socialist Party TD, Mr Joe Higgins, who with Ms McKenna opposed holding the two referendums on the same day, said the decision was "despicable". "The Government's sleight of hand here is ensuring the real agenda of the Amsterdam Treaty in regard to the creation of a European army and armaments industry, for example, will not be able to be spelt out fully."
Calling for an enthusiastic Yes vote, Mr Andrews said the treaty would commit EU member-states to co-ordinated action to attain a high level of employment. Its social policy would "allow for EU action to deal with the serious Europe-wide problem of social exclusion".
Meanwhile, the Labour MEP, Ms Bernie Malone, last night called for a referendum to overturn the McKenna judgment, which prevents the State from funding partisan Yes or No campaigns.
She said the folly of the judgment was clear in both referendums. "They are enthusiastically supported by all the major political parties and yet the Government must use taxpayers' money to tell the people why these agreements are not in their best interests and why they should vote against them."
A Labour Party spokesman said holding the referendums together would maximise the turnout and save money, while holding the polls on a Friday would allow students and those working away from home to return to vote.