Estonia is to ratify the European Union's troubled constitution in May, the leaders of the Baltic state's ruling three-party coalition said Monday.

"The final vote on the EU constitution will take place in May, thus concluding the ratification process in the parliament," Meelis Atonen, deputy head of the Reform Party, told AFP.

The decision was taken by leaders of the Reform Party, the Centre Party and the People's Union, the three groups that make up the coalition government and command a majority in parliament.

The parliament in Estonia, one of 10 countries that joined the EU in May 2004, began the process of ratifying the constitution in February, but no deadline had previously been set for the final vote.

"With this ratification process we are showing other EU member states that the constitution is needed by the EU," Estonian Foreign Minister Urmas Paet told lawmakers when the ratification process started.

The EU constitutional treaty, which has been approved by parliaments in 14 countries, has to be endorsed by all 25 member states to come into force.

Initially, the deadline for all member states to ratify the constitution was set for November this year, but after French and Dutch voters rejected the treaty last year, EU leaders agreed to have a "period of reflection" on the constitution, which was to set new ground rules and streamline decision-making in the enlarged bloc.

Fourteen member states have ratified the treaty so far: Austria, Belgium, Cyprus, Germany, Greece, Hungary, Italy, Latvia, Lithuania, Luxembourg, Malta, Slovakia, Slovenia and Spain.