(CNN) -- European leaders signed a new treaty in Lisbon, Portugal on Thursday to reshape the European Union and streamline decision-making, despite criticism that the treaty strips member nations of too much power.
German Chancellor Angela Merkel, left, and German Minister of Foreign Affairs Frank-Walter Steinmeier shake hands.
Leaders of the EU's 27 member nations approved the treaty in October. It is the would-be successor to the proposed EU constitution that was scrapped in 2005 after voters in France and the Netherlands rejected it.
While the national parliaments in each member nation must still ratify the treaty's final text, it will now go to voters in only one nation -- Ireland, where the country's constitution requires a public referendum.
The lack of referenda in other member nations has caused controversy, mostly in Euro-skeptic countries like Britain, where vocal critics have been demanding a public vote.
The headline in Thursday's edition of The Sun tabloid in Britain read, "Never have so few decided so much for so many."
The treaty changes voting procedures, increases the role of the European parliament, and includes a charter of fundamental rights.
Reforms include extending the length of the rotating presidency of the European Council from six months to 2 1/2 years, and combining into one role the posts currently held by foreign policy chief Javier Solana and External Relations Commissioner Benita Ferrero-Waldner.
Opponents, however, believe it hands too much power to the EU's institutions. The UK campaign group "I Want a Referendum" says that for Britain, the treaty would weaken the country's ability to veto EU laws and give Britain less control over matters including foreign policy, defense, and immigration.
"We want a referendum on the whole thing," said Neil O'Brien, who heads the group.
Portuguese Prime Minister Jose Socrates, whose country currently holds the rotating EU presidency, disputed the treaty's critics.
"The European project does not eliminate or minimize national identities, nor the states' specific interests," he said Thursday. "Rather, it offers a multilateral framework of regulation from which benefits can be drawn for the whole and for each of the parts."
Supporters believe the treaty offers simple, necessary reforms to help the EU operate more efficiently.
"By resolving its institutional issues, the European Union is preparing itself to serve its citizens better and to address global issues," said European Commission President Jose Manuel Barroso before the signing.
O'Brien said the treaty is no different from the rejected EU constitution, on which Britain's ruling Labor Party had promised a referendum. Prime Minister Gordon Brown has said he does not intend to put this treaty to a public vote.
"Gordon Brown knows that people don't want the treaty, and knows they're unhappy," O'Brien said. "(That's why) he's gone back on his promise." E-mail to a friend