Alternattiva Demokratika and Partit Demokratiku have formally merged, adopting the name AD+PD and electing former Green Party head Carmel Cacopardo as the new party's first chairperson.
AD+PD held its first AGM on Saturday, where it confirmed its first executive committee, headed by Cacopardo with Mario Mallia and Mark Zerafa as deputies.
The party said it would be undergoing an initial transition period "establishing a new identity based on the progressive principles of environmental justice, social justice, good governance, solidarity, non-violence, sustainability, rule of law, accountability, transparency and a respect for diversity".
It will form part of the European Green Party.
The rest of the executive committee will be made up of Ralph Cassar as secretary general, Luke Caruana and Melissa Bagley as deputies, Marcus Lauri as PRO, Carmel Axiak as treasurer, and Anna Azzopardi as international secretary.
Duncan Bonnici, Martina Caruana, Sandra Gauci, Donal Kelly, Jamie Mercieca, Matthew Mizzi and Mina Tolu form part of the committee as members.
The new party faces an uphill struggle to establish itself. At the last general election, AD and PD received 0.8% and 1.6% per cent of the vote, while PD were running on the Nationalist Party ticket as part of an electoral coalition.
Recent surveys indicate the two parties' vote shares have dropped significantly since then.
Historically, AD's best general election result since its formation in 1989 came in 2013, when it obtained 1.8% of the vote.
The party also secured 9.3% of votes in the 2004 European Parliament elections, when candidate Arnold Cassola narrowly missed out on election.
PD, formed by former Labour MP Marlene Farrugia in 2016, received 2.03% of votes at the 2019 European Parliament elections.
The election of Farrugia and Godfrey Farrugia to Parliament in 2017, albeit on the PN ticket, marked the first time a third party had succesfully elected MPs since 1962.
Amended: a previous version of this article misstated the name of secretary general Ralph Cassar.