Irish voters are likely to reject the Nice Treaty for the second time causing the treaty to be scrapped, according to a new report by the Economist Intelligence Unit (EIU).
The research unit of the respected Economistmagazine said the likely "No" vote will convulse the EU, raising fresh doubts about its enlargement and lead to one of the most serious diplomatic crises in Ireland's history.
The report said although opinion polls consistently show most Irish people in favour of the treaty, the far more motivated minority who oppose the treaty will turn out to vote in greater numbers.
"Given that only 43 per cent bothered to vote in March 2002 on the far more emotive issue of how abortion should be regulated, it is very difficult to see turnover in the second Nice poll picking up much from the 34 per cent registered in the first referendum," the report said.
The report said the Irish public - 9 out 10 of which believe Ireland has benefited from EU membership - are turned off by the complexity of the treaty, which offers little obvious incentive to vote in favour of the treaty, even for those who are generally well disposed towards the EU.
"If there are no carrots with which advocates of the treaty can coax the electorate out to vote, neither is there, in theory at least, a stick to hasten them to the ballot boxes, " the EIU said.
After an emotive abortion referendum and long general election campaign Irish voters are unlikely to be enthusiastic about Nice 2, according to the EIU.
The report also cites a growing euroscepticism among Ireland’s political class driven by the belief that Ireland's recent boom has more to do with US-style economic policies than with EU membership.
The report warns rejection would plunge the EU into a constitutional crisis with Ireland shouldering the blame. "Causing such a headache will incur the wrath of fellow members states, particularly as Ireland is recognised (and often resented) as one of the countries to have got the most from EU membership."
The report warns: "Worse still for Ireland, questions may well be asked about its continued membership if voters in the Union's second smallest member state look like blocking future treaty changes.
"In a worst-case scenario, this could make Ireland a less attractive investment location. Jobs and prosperity would then be threatened".