The Free Democratic Party (FDP), which could form a coalition with Chancellor Angela Merkel's conservatives after parliamentary elections next month, issued a statement criticizing the Afghan mission.

Juergen Koppelin, an FDP member with responsibility for defense issues, told the Wednesday edition of Germany's mass-circulation Bild newspaper that the NATO mission in Afghanistan lacked a clear strategy and had produced too many victims.

"The next government must formulate a precise plan that spells out how a pull-out of the German army over the coming years would look," Koppelin said.

"Our soldiers operating in Afghanistan and their families need to know that the mission will end," he added.

Merkel's Christian Democrats (CDU) have refused to fix a timeline for a withdrawal. Defense Minister Franz Josef Jung has said German troops could stay another five to 10 years.

By criticizing the current policy on Afghanistan, the FDP - whose leader Guido Westerwelle is expected to become foreign minister should the conservatives choose the liberals as their next coalition partner - puts itself in opposition with the party which could bring it into government.

Rocking the boat

The latest opinion poll, from Emnid, shows Merkel's conservative bloc with 36 percent of the vote, enough support to win a parliamentary majority, with the FDP at 14 percent. Current coalition partners, the Social Democrats (SPD), are trailing the conservatives with 23 percent.

Should the FDP join with the CDU after an expected conservative election victory next month, the center-right, pro-business party is likely to wield significant influence over Germany's foreign policy.

The Afghanistan mission is highly controversial in Germany, which has about 4,200 troops in Afghanistan, with polls showing close to two-thirds of Germans oppose it.

So far, the mission has not been a major issue in the election campaign, in part because the two biggest parties - the CDU and Social Democrats (SPD) - agree the troops must stay.

A parliamentary mandate, which allows Germany to contribute up to 4,500 troops to the NATO mission, expires in December and must be renewed if the troops are to remain in Afghanistan.

nda/Reuters/AP

Editor: Kyle James