BERLIN — German Chancellor Angela Merkel's government is arguing about pensions, with Merkel's center-left coalition partners pressing for a guarantee that they will remain stable until 2040.

The coalition of Merkel's conservative Union bloc and the center-left Social Democrats agreed when it took office earlier this year to ensure pensions remain at the current level of 48 percent of average wages through 2025.

The Social Democrats are struggling in polls and looking to woo left-leaning voters. Finance Minister Olaf Scholz, a Social Democrat, has called for stable pensions to be guaranteed through 2040, a potentially expensive pledge in an aging society.

Conservatives note the coalition already set up an expert commission to look at future pensions. Merkel told ARD television Sunday her message to the Social Democrats is: "Please don't create uncertainty."