BERLIN (Reuters) - German lawmakers from the center-left Social Democrats (SPD) and two smaller parties met on Sunday to explore the possibility of forming a coalition government to replace Chancellor Angela Merkel next year.

German Chancellor Angela Merkel attends the weekly cabinet meeting at the chancellery in Berlin, Germany, December 9, 2016. REUTERS/Hannibal Hanschke

The SPD, environmentalist Greens and leftist Linke party already have more seats in parliament than Merkel’s conservative bloc but divisions at federal level - especially on foreign policy - have prevented them from forming a national government.

Merkel currently leads a right-left coalition of her conservatives - the Christian Democrats (CDU) and their Bavarian CSU allies - and the smaller SPD.

Merkel, whose popularity slumped after Germany let in 890,000 migrants last year, will seek a fourth term in office in a national election due in autumn 2017.

Sunday’s meeting marked the second time the left-leaning lawmakers have held exploratory talks and came after Merkel’s CDU moved to the right at a party conference last week, at which she called for a ban full-face Muslim veils.

Axel Schaefer, deputy leader of the SPD’s parliamentary group, said the three left-leaning parties were not yet aiming to nail down a specific policy program.

“This is about the general direction of a progressive policy,” he told reporters before the talks in the Bundestag.

The meeting, at which the lawmakers planned to talk about employment and social justice, also came after the same three parties last week joined forces in a so-called ‘Red-Red-Green’, or ‘R2G’, coalition to take control of Berlin’s city government.

“We think the government formation in Berlin can give the project R2G a push at the federal level,” said Thomas Nord of the Linke, adding: “We know that we still have a lot of questions to discuss with each other.”

The parties plan to meet once a month next year.

Merkel, 62, told the CDU last week it needed to be strong to resist the threat of a Red-Red-Green coalition.

A survey of 2,426 voters published by pollster Emnid on Saturday put support for the conservatives at 36 percent, the SPD at 22 percent, and the Greens and the Linke both at 10 percent. The anti-immigration Alternative for Germany (AfD) scored 13 percent and the liberal Free Democrats (FDP) five percent.

Frithjof Schmidt of the Greens said the three left-leaning parties could capitalize on what he said was dissatisfaction among many voters with the CDU’s shift to the right at its party conference last week.

“Both that and the government formation in Berlin give momentum to Red-Red-Green,” he said.