Voters in Ireland turned down the Lisbon Treaty agreed by European Union leaders in December 2007, preliminary results of the June 12 referendum showed, as quoted by international media.

A number of senior Irish government officials conceded defeat on June 13 as results began trickling in. "It looks like this will be a 'no' vote," justice minister Dermot Ahern told RTE television, as quoted by Reuters. "At the end of the day for a myriad of reasons the people have spoken."

With results in from 33 of the 43 constituencies, RTE said, 53.7 per cent of Irish voters voted against the treaty, which was drafted make the EU institutions more efficient and streamline decision-making after the the bloc's expansion eastward. Ten countries joined the EU in 2004, with Bulgaria and Romania being the latest additions as of January 1 2007.

Final figures are expected to be released later in the day, but initial data showed that supporters of the treaty won only in the better-off areas of capital Dublin, according to RTE.

Ireland is alone among the 27 member states of the EU that put the treaty up for plebiscite, as required by the country's laws. The rest of the bloc's countries decided that ratificaiton would be handled by national parliaments, wary that the treaty would face the same fate as the draft European constitution, shot down by French and Dutch voters at referendums in 2005. The Lisbon treaty comes to replace the constitution.

The treaty has been approved by 14 member states, while four more have started the process. All member states have to approve the treaty before January 1 2009, when it is due to go into force.

Analysts fear that the Irish 'no' could spell a new political crisis for the EU and delay the much-needed reforms in the way the bloc's institutions work.