An alliance of three left-leaning parties has laid out the cornerstones for its coalition government in the German state of Berlin, revealing plans to invest in schools, housing and integration of migrants.

The center-left Social Democratic Party, environmentalist Greens and ex-communist Left party won enough seats in September's vote for a majority in the German capital's assembly.

Another German state, Thuringia, became the first to get such a governing coalition in 2014.

Some left-wing politicians are proposing the parties could form a national government following next year's general election.

The leader of Chancellor Angela Merkel's center-right Christian Democrats in the Berlin assembly, Florian Graf, said Thursday his party would consider voting with the nationalist Alternative for Germany, if necessary.

AfD won over 14 percent of the state vote in September.