Andrew Duff, a British member of the European Parliament and the Liberal Democrat spokesman on constitutional issues, said that the treaty’s defeat had been a “tragedy” for the grand project that is the European Union.
“The problems the treaty was established to address are still there: effectiveness, democracy and the capacity to act,” he said in an interview. Referring to the 2001 Nice Treaty, which last reorganized the way the union functions, he said: “If the outcome of this is that we are obliged to struggle on with the existing treaty, then the Irish have done no favors for themselves or us.”
It is unclear what exactly will happen next. Ireland is the only country to put the Lisbon Treaty to a referendum, as its law requires. In general, such treaties are far more popular with Europe’s leaders than with its voters, and most governments are reluctant to risk the uncertainty of a national vote.
The other 26 countries in the European Union are considering it through their legislatures and executives, and 18 have approved it so far.
Around Europe, pro-treaty officials reacted to the vote with a collective brave face, vowing to forge ahead with the Lisbon Treaty despite Friday’s possibly fatal setback.
In 2001, Ireland initially rejected the Nice Treaty in a similar referendum to the one on Friday, but was prevailed upon to change its mind in a second referendum the next year.
There is no suggestion yet that that might happen again. But in Brussels, the president of the European Commission, José Manuel Barroso, said he believed that the treaty was still “alive.” In Paris, Jean-Pierre Jouyet, France’s minister for European affairs, said that “the most important thing is that the ratification process must continue in the other countries, and then we shall see with the Irish what type of legal arrangement could be found.”
A referendum in Ireland proposing the country's ratification of the Treaty of Lisbon  has been rejected by the electorate despite near universal support from the country's political establishment. 

Although in most states the issue has been (or will be) decided through parliamentary vote, Ireland was obliged to hold a referendum by its constitution. Ireland is the first state to reject the treaty which came about as a reworking of the E.U. Constitution, rejected by referenda in France and the Netherlands in 2005.

862,415 cast their vote against the treaty and 752,451 people voted for it, yielding a 53.4% to 46.6% margin of defeat. All 43 constituencies have been counted.

"It looks like this will be a No vote," Dermot Ahern, the Irish Minister for Justice said on live television. "At the end of the day, for a myriad of reasons, the people have spoken."

"The Treaty is not dead," said European Commission President José Manuel Barroso. "The ratification process is made up of 27 national processes, 18 Member States have already approved the Treaty, and the European Commission believes that the remaining ratifications should continue to take their course," he said.

"Ireland remains committed to a strong Europe," said Barroso after speaking with Taoiseach (prime minister) Brian Cowen. "Ratifications should continue to take their course."

France and Germany issued a joint statement expressing regret over the result. The United Kingdom said it would continue with its own ratification process.