German reaction: Chancellor Gerhard Schröder called the French referendum result a "setback for the constitutional process but not its end".
"I very much regret the result of the French referendum, but the will of the voters must be respected. The ratification process of the member states must continue," said Mr Schröder in a statement.
"It is also not the end of the German-French partnership in and for Europe. I have already shared this view with the French president, Jacques Chirac."
Foreign minister Joschka Fischer said Berlin had hoped for a Yes in the referendum, "because it is a good treaty", he said. "I take it that the [ ratification] process will be carried through to the end."
Germany ratified the constitutional treaty last Friday after a two-stage parliamentary vote instead of holding a referendum. There has been little discussion of the constitutional treaty in the media and news of its ratification was a two-day wonder in the newspapers.
Leaders of Germany's opposition Christian Democrats (CDU) said the French vote was a rejection of Turkey's EU accession hopes.
CDU leader Angela Merkel said it showed how alienated people feel from the EU and the current uncertainty about where Europe's borders end. "We need an honest discussion about Turkey's membership of the EU," she said. CDU foreign spokesman Wolfgang Schäuble said: "We now have a crisis and we must learn the right lessons from it because it is a chance for Europe to continue to make progress."
Guido Westerwelle, leader of the liberal Free Democrats, said: "This is a serious setback for our German project of advancing European unification."
Martin Schulz, the German leader of the Social Democrats in the European Parliament, said: "With no, the French have voted against the possibility of creating a better Europe." Behind closed doors back at the European Commission's Berlin headquarters, adjacent to the Brandenburg Gate, officials were less diplomatic about the French vote.
One leading official joked that it reminded him of the famous quote of one British politician: "The people have spoken. The bastards."
EU internal market commissioner Charlie McCreevy called the French rejection a "disappointment but not a crisis".
He said that other member states should be allowed go through their ratification procedures and that the French vote would not influence the commission's plans to liberalise the European services market.
"Let's draw a breath and reflect. Politicians should not complain when people exercise their democratic rights," said Mr McCreevy in Berlin yesterday.
"I would hate to think [ the French vote] is about not moving forward on the common market but that the outcome of the debate would move us even further back." The wide focus of the French referendum debate had similarities to the Irish rejection of the Nice Treaty, he said.
"Nice was about enlargement but you had to look high and low for a mention of it [ in the campaign]. All other issues got dragged in," he said.
He rejected suggestions the French vote was a No to a perceived economic liberal direction of the European integration. EU economic policy was, he said, based on the simple reality that the EU is not growing at a level to sustain the current social model.