Germany's center-left Social Democrats say new members who join by Feb. 6 will be allowed to vote in a ballot on whether to join conservative Chancellor Angela Merkel's next government.

The Social Democrats and Merkel's Union bloc aim to conclude coalition talks Sunday, but may take longer.

Leading Social Democrats are treading cautiously amid discontent after the party was thrashed in September's election. They have held two party conferences to get this far, and promised a ballot of the roughly 440,000-strong membership on a coalition deal. The party's youth wing, which opposes a new coalition, has been urging people to become members.

The party's general secretary, Lars Klingbeil, said after party leaders met Monday that members who are in the party database on Feb. 6 will be eligible to vote.