Germany's conservatives won the national election on Sunday, while the far-right Alternative for Germany came in second, its best ever result.

Polls are open across Germany as the world’s third largest economy chooses a new leader to guide it through an era of febrile immigration debates and souring relations with Washington.

The conservative Christian Democratic Union (CDU) leads the polls with an estimated 29% of the vote, going by the exit polls, while the incumbent Social Democratic Party (SPD) is third with 16%.