The European Union's Lisbon Treaty should come into force by April 2009, Danish Prime Minister Anders Fogh Rasmussen said Thursday ahead of an EU summit in Brussels, according to dpa. "This is a very optimistic and ambitious timetable," Rasmussen said at a pre-summit meeting of European Liberals. The adoption of the treaty by April would allow the next European Parliament to be elected in June according to the new rules. The treaty was originally intended to come into force in January, but Ireland's rejection of the text in a June 12 referendum has thrown that deadline into question. Irish Prime Minister Brian Cowen was due to brief his colleagues about the outcome of the referendum over dinner. He has asked for more time to analyze the consequences of the vote, and European Commission President Jose Manuel Barroso has said a solution will not be found until October.