Czech President Vaclav Klaus signed the EU"s Lisbon Treaty today, removing the last barrier to the bloc"s plan to overhaul its institutions and win a bigger role on the world stage, according to Reuters. Klaus was the last EU leader to ratify the treaty and his signature means the bloc of nearly half a billion people can now focus on picking its first president and a more powerful foreign representative to speak for it on global affairs. The treaty, with roots in the failed European Constitution rejected by voters in two member states in 2005, is aimed at making the European Union more flexible and a stronger player on the world scene, to match the rise of emerging powers like China. The staunchly eurosceptic Czech president signed the pact after the country"s Constitutional Court had thrown out a complaint against it earlier in the day. "I had expected the court ruling and I respect it, although I fundamentally disagree with its content and justification," Klaus told reporters. "I signed the Lisbon Treaty today at 1500 (local time)." The Swedish EU presidency said the treaty would take effect in December, turning attention to the choice of the bloc"s first president. Swedish Prime Minister Frederik Reinfeldt said he would call an EU summit to discuss possible appointments under the treaty.