Portugal will go ahead with a referendum on the European Union's constitution slated for October despite the rejection of the treaty by voters in France and the Netherlands over the past week, Prime Minister Jose Socrates said Thursday.

"In Portugal we maintain our intention to hold a referendum at the same time as the next municipal elections," he told reporters at a joint press conference with his visiting East Timorese counterpart Mari Alkatiri.

"The opinion expressed by the Dutch people in the referendum on Wednesday was a disappointment for all those who believe that deepening European integration must be done through ratification of the treaty," he added.

He said the European Union needed to reflect on why the treaty was rejected by voters in these two nations.

"This is a difficult time for Europe which deserves a response on a European scale," he added.

Dutch voters overwhelmingly rejected the treaty, which needs approval by all 25 EU member states before taking effect, with 61.6 percent turning it down.

In a referendum held Sunday in France nearly 55 percent said "no".

The EU constitution, designed to streamline the way the expanding bloc is run, has so far been ratified by 10 countries including Austria, Greece, Hungary, Italy, Latvia, Lithuania, Slovakia, Slovenia, Spain and Germany.