Chancellor Angela Merkel's conservatives and the Greens are setting out contrasting positions on migration as the prospective partners in a new German government seek compromises to enable a coalition.

Merkel's Union bloc, the pro-business Free Democrats and the traditionally left-leaning Greens aim to decide this week whether to start formal coalition negotiations. Migration — particularly whether to allow relatives to join people granted protection that falls short of asylum — is one main sticking point.

Those people can't currently bring relatives to Germany, and Merkel ally Volker Kauder said there's "no room for maneuver." He told Tuesday's Passauer Neue Presse newspaper 300,000 people could apply to come.

Prominent Green Claudia Roth told ARD television the right to a family "is a fundamental right." She said it's likelier 50,000-70,000 people would come.