BRUSSELS, November 3 (RIA Novosti) - Czech President Vaclav Klaus signed the EU's Lisbon Treaty on Tuesday after the country's Constitutional Court ruled that the ambitious reform treaty was in line with the Czech constitution.

The agreement was signed in the Portuguese capital on December 13, 2007, and introduces fundamental changes to the workings of the European Union. With the Czech president's signature, it has now been ratified by all 27 EU member states.

The president of the European Commission, Jose Manuel Barroso welcomed earlier Tuesday the Czech Republic's Constitutional Court decision.

"I believe that no further unnecessary delays should prevent the entry into force of the Lisbon Treaty," Barroso said in a statement.

The Czech court rejected a complaint filed by 17 senators, who said the treaty did not conform to the constitution.

Euroskeptic Klaus had opposed the treaty as a threat to his country's national sovereignty, demanding, among other things, an opt-out from the EU Charter of Fundamental Rights over fears that the Czech Republic would be swamped by property claims from Germans expelled after World War II.

EU leaders agreed to the opt-out last week.