Simone Peter, co-leader of Germany's Greens | John MacDougall/AFP via Getty Images German Greens hit back at FDP over migration spat Christian Lindner’s rhetoric on refugees is stalling coalition talks’ progress, says Simone Peter.

The German Greens fired back at Christian Lindner's Free Democrats late Wednesday over the two parties' disagreement on migration, accusing the FDP leader of peddling "populist platitudes" and obstructing coalition talks.

Simone Peter, co-chair of the Greens Party, told Berliner Zeitung that negotiations among the four potential coalition partners can't "seriously move forward" amid Lindner's comments on migration and refugees.

Lindner, whose FDP takes a much harder line on migration issues than the Greens, earlier this week called the Greens’ immigration plan — and in particular, their support for family reunification for refugees — a boon to the far-right, anti-immigration Alternative for Germany (AfD).

“The position of the Greens isn’t supported by a majority of the population, and is a stimulus for the AfD,” he told Bild newspaper Wednesday. He also put the chances of a successful coalition between the four parties — the FDP, Greens, and Chancellor Angela Merkel’s CDU/CSU alliance — at “50-50.”

Two weeks into coalition talks, migration remains one of the most contentious issues among the four parties, with a discussion last week yielding no agreement. Some of the thornier topics include whether there should be an upper limit to the number of refugees allowed into the country (the so-called Obergrenze), as well as the question of whether to allow spouses and children to join refugees already in Germany.

According to new figures out Thursday from the German government, 1.6 million people sought asylum in Germany by the end of 2016, a 113 percent increase compared to 2014.

Roughly half of the asylum seekers registered as of 2016 came from Syria (455,000), Afghanistan (191,000) and Iraq (156,000). Close to two-thirds are men, according to the data.

This article was updated to clarify the dates referenced by the migration data cited.