German voters are choosing their new government in an election dominated by worries about the years-long stagnation of Europe's biggest economy, pressure to curb migration and growing uncertainty over the future of Ukraine and Europe's alliance with the United States.

This important election has galvanised voters, and campaigning resumed on Saturday evening with a final discussion on national television, the ninth of the month

Germany's mainstream political parties lost support while the far-right AfD gained ground in one of the last polls published before the election on Sunday, pointing to likely tricky coalition building that could drag on for months.

Alice Weidel's Alternative for Germany (AfD) could become the second-largest party in the German parliament after Sunday's vote.