Two days later, on 9 May, representatives of a dozen European parties gathered at the UDF headquarters in Paris to celebrate 'Europe Day' and lay the foundations of the new European party.
A few days after the elections and after a meeting with Graham Watson, president of ALDE, to prepare the new party's entry into the new parliamentary group, François Bayrou called a press conference with Francesco Rutelli to launch the PDE. The founding general assembly of the PDE will take place on , a 13 July 2004 date that coincides with the start of the European legislature. The founding parties are the UDF, the Margherita, the MCC, the Lithuanian Labour Party, the Czechs of Path of Change and the Cypriots of New Horizons, for a total of 25 MEPs within the 88-member 'Group of the Alliance of Liberals and Democrats for Europe'. On 11 September, the Margherita National Party closed in Monopoli, Italy, with a debate on European issues: among the speakers were Josu Jon Imaz, then president of the Basque PNV , Francesco Rutelli and François Bayrou. Radio Radicale recorded the event.