HELSINKI, Finland — Sanna Marin, 34, is set to become the world’s youngest sitting prime minister when she is sworn in this week in Finland, after being elected to the position by her party late Sunday.
The country’s coalition government consists of five parties, four of which are led by women, with Ms. Marin now at the helm.
“The past week has been extraordinary,” she told reporters, according to Helsingin Sanomat, a leading Finnish newspaper. “Now is the time to look ahead. What is needed now is action beyond words to build trust from all government parties.”
Formerly the country’s transportation minister, Ms. Marin was voted in by fellow lawmakers in her Social Democratic Party after a turbulent week in which Prime Minister Antti Rinne resigned over his handling of a postal workers strike.
Although Mr. Rinne will continue as head of the party, Parliament is expected to confirm Ms. Marin as prime minister as soon as Tuesday, depending on how quickly the other coalition parties name their ministers. Once sworn in, she will be Finland’s youngest prime minister to date and its third female prime minister.
Ms. Marin, a left-leaning liberal, has been a member of Parliament since 2015. She began her political career in 2012, when she was elected to the local council in the southern city of Tampere. Most recently she was minister of transportation and communications in Mr. Rinne’s government.
Serving as Mr. Rinne’s deputy when he took an extended sick leave in earlier this year, she helped lead their party to a narrow win in national elections.
Alexander Stubb, who was Finland’s prime minister from 2014 to 2015, posted on Twitter that having a government led by women “shows that #Finland is a modern and progressive country.”
“One day, gender will not matter in government,” he wrote. “Meanwhile pioneers.”
Of the five women in leading ministerial positions in the coalition, four are under 35. Asked about her age after it was announced that she would be prime minister, Ms. Marin reiterated what she has said numerous times: Age doesn’t matter.
“I have not actually ever thought about my age or my gender,” she said, according to the national news outlet YLE. “I think of the reasons I got into politics and those things for which we have won the trust of the electorate.”
Ms. Marin won the leadership vote by a small margin, and her skills will be put to the test immediately as the country heads into a season of labor negotiations with the potential for strikes. Her predecessor, Mr. Rinne, was ultimately forced out of office after he made comments about a plan to cut wages for postal workers and his coalition partner, the Center Party, said it had lost confidence in him.
Despite his resignation, the coalition’s parties will remain unaltered: Ms. Marin’s Social Democratic Party as Finland’s biggest, the Center Party, the Greens, the Left Alliance and the Swedish People’s Party of Finland.
The Social Democratic Party will vote at its convention next June to determine whether Mr. Rinne will continue to lead the party or whether Ms. Marin or someone else will formally take over.
The coalition government under Ms. Marin is expected to continue prioritizing job creation and ambitious climate goals, seeking to render Finland carbon neutral by 2035.
Johanna Lemola reported from Helsinki and Megan Specia from London.