At its electoral debut at the 1999 European Parliament election, the party received 1.6% of the vote, having its strongholds in the South (5.1% in Campania, 3.4% in Basilicata, 4.4% in Calabria and 7.1% in Sicily).

Under the leadership of Francesco Rutelli, who ran also as leader of the entire The Olive Tree centre-left coalition, DL gained 14.6% of the vote.

Most leading members, including Antonio Satta (who would later launch the Christian Popular Union), Stefano Cusumano, Mauro Fabris, Armando Veneto and Tommaso Barbato, left.

At the 2008 general election both The People of Freedom (PdL) and the Union of the Centre (UdC) refused the UDEUR as coalition partner.

The latter included Giulio Di Donato, a former leading figure of the Italian Socialist Party, who was appointed regional secretary in Campania.

[20][21] In 2020, Mastella re-branded the party under the name Us Campanians (Noi Campani), taking part in the 2020 Campania regional election in support of the Democratic governor, Vincenzo De Luca.

In 2021, Mastella launched a new political party in order to compete in countrywide elections: Us of the Centre (Noi di Centro).