BERLIN (AP) — Franziska Giffey, a former federal minister who quit Germany's national government earlier this year, became Berlin's new mayor on Tuesday as the leader of a three-party left-wing governing coalition.

Giffey was elected by the state legislature nearly three months after a regional election in which she led her center-left Social Democrats, the party of new German Chancellor Olaf Scholz, to a narrow victory over the environmentalist Greens.

Giffey, 43, served as minister for women and families in ex-Chancellor Angela Merkel's last government until she resigned in May amid allegations of plagiarism in her doctoral thesis. She was later stripped of her doctorate, but stuck to her longstanding plan to run for mayor.

She said at the time that she wrote the thesis “to the best of my ability” and mistakes she made weren’t intentional or planned.

Giffey was already well known to Berliners before she joined the national government in 2018 as the popular mayor of the German capital's Neukoelln district, which has a high poverty rate and many families with an immigrant background.

As Berlin mayor, she has identified housing as a top priority. Rising rents have long been a top issue in Berlin. Giffey's new government will have to decide what to do with the result of a nonbinding September referendum in which voters backed a call for the local administration to expropriate about 240,000 apartments from corporate owners.

Giffey's coalition with the Greens and the Left Party isn't united on that issue. It has tasked an expert commission to make a recommendation.

It's the same combination of parties that formed the capital's sometimes fractious government for the past five years, but with mostly different faces after Giffey's predecessor, fellow Social Democrat Michael Mueller, won a seat in the national parliament. He didn't seek another term after governing the city for seven years.

Giffey is the first woman to be elected as mayor though not the first to lead the city. Louise Schroeder, then the deputy mayor, stepped up to the top job in 1947-48 after the first post-World War II mayor resigned.