The European Parliament (EP) on Wednesday approved the European Union (EU) constitution.

By vote of 500 to 137 with 40 abstentions, EP members gave their approval to the constitution whose draft was finalized at the EU Brussels summit in June 2004.

The EP's ratification, despite being non-binding, will serve as a "key point of reference" for the 23 EU member states which have still to ratify the constitution in the coming months, in many cases by referendum, said the EP in a press release.

Lithuania and Hungary have already ratified the constitution.

The constitution will come into effect as of Nov. 1, 2006 providing it is ratified by the EP and all EU member states.

Approved by leaders of all 25 EU member states on Oct. 29, 2004,the constitution covers the EU's organization, the decision-making mechanism and the rights of EU citizens.