The Blue Reform group, which split off from the populist Finns Party in June, was officially approved as a political party on Wednesday.
The Ministry of Justice has entered it into the party registry, where it became Finland's 17th party.
Party chair Sampo Terho and MPs Tiina Elovaara and Matti Torvinen presented the required minimum of 5,000 supporters' cards to the ministry on October 16.
Terho, 40, is a former MEP who became Minister for European Affairs, Culture and Sport in May. The following month, he and 20 other Finns Party MPs quit their party to form a new group, initially called the 'New Alternative'. They included the nationalist Finns Party's founder and long-time chair Foreign Minister Timo Soini, as well as Defence Minister Jussi Niinistö, Employment Minister Jari Lindström and Minister of Social Affairs and Health Pirkko Mattila.
The right-leaning Blues say their main goals are lower income taxes, controlled immigration and defending the rights of Finns in EU policy. They are scheduled to announce the date of their first party congress within the next few days.
The latest Yle opinion survey showed negligible backing for the new group, with the Finns Party support dropping below seven percent.