The leader of Fine Gael has asked the public to "do the decent thing" and vote Yes in the forthcoming referendum on the Nice Treaty.

Mr Enda Kenny accused the Government of being the "single biggest threat to a Yes vote". He could see how the "poor and often sloppy transposition of EU directives into Irish law was having an impact on the public's perception of Europe".

Mr Kenny also criticised the Green Party for its "quite extraordinary stance" because it was the Green agenda that had gained most from the EU, "with a raft of environmental initiatives on water, air, waste and noise".

Quite simply, "when it comes to Europe Fine Gael believes", Mr Kenny declared. The Irish "are a noble nation", with a separate and ancient heritage, but "we are also realists. We know how critically our involvement has boosted our influence socially, politically and economically." He was speaking during the four-day Dáil debate on the legislation to pave the way for the referendum.

He acknowledged, that "an enlargement of sorts can happen without Nice. Some candidates would be admitted. Others, who are equally ready, would not. Such rejection could have seriously political consequences for these fragile democracies."

Mr Kenny said that with a Yes vote "we can send a message to Europe and the world that, in Ireland, we believe no country to be more equal than another. To do that we must vote Yes." He said the EU had gone from six to 15 members. "Now, the Union needs a new injection of economic opportunities and it will get that through enlargement."

He appealed to women, "the repository of wisdom in this country", to vote Yes. The EU had driven the equality agenda, including the charter for equal pay, but in critical areas such as childcare, maternity and paternity leave, and family-centred work arrangements, "we're trailing miserably behind our EU partners".

He said Ireland needed Europe and "Europe needs us". In the referendum the public would make a "historic and momentous decision that will affect the lives and the social and economic well-being of millions of people across this Continent.

"It is we, and we alone, can decide how the great European project, one that has brought 50 years of peace, stability and prosperity to this Continent, is to develop. The eyes of the world are on us. There is no Plan B."

He told the Dáil he wanted to "debunk the prevailing myth" that Ireland all by itself created the tiger economy. "Not a bit of it. To say we have, it to delude ourselves utterly." The EU, "more than any other single factor, made us the economic success we are today". It had underpinned "our marvellous economic transformation." People who said that Ireland did not need Europe now "are all wrong". If that view were upheld "it would be fatally damaging, not alone to our already faltering economy, but to Ireland's continued influence on global affairs".

Ireland has only 1 per cent of the EU population but "we attract 6 per cent of American investment to Europe". An estimated 100,000 Irish jobs are dependent on US investment and it was important to maintain and increase that US commitment to Ireland, its nearest EU neighbour.

If Ireland becomes semi-detached from Europe it will not just be silent "but silent and irrelevant". What happens in New York or Baghdad affects everyone's life and in a matter of hours. "Because of that, a powerful independent European voice is both necessary and desirable," Mr Kenny said.