BERLIN (AP) — Chancellor Angela Merkel's conservatives are sitting down for a final day of talks with their prospective center-left partners to try to determine if there is enough common ground to begin formal coalition negotiations.

Merkel's Union bloc and the Social Democrats have been meeting behind closed doors this week, with Thursday's final round of talks expected to focus on the thorny questions of migration policy, health care and finance.

Social Democratic lawmaker Ralf Stegner tweeted ahead of the talks that the sides met until just before midnight Wednesday, with the intensity increasing and progress being made, albeit slowly.

Should the two sides not be able to form a coalition, it opens up the possibility of a minority government under Merkel or new elections.