Chancellor Angela Merkel's conservatives and Germany's main center-left party were still haggling Wednesday over a deal to form a new coalition government after negotiations that lasted through the night.

There was no sign of an imminent end to talks between Merkel's Union bloc and the Social Democrats, some 23 hours into what party leaders have said should be the final round of negotiations. A meeting in Berlin between Merkel and Italy's premier, originally scheduled for lunchtime, was postponed until the late afternoon.

"Progress is a snail," Ralf Stegner, a deputy leader of the Social Democrats, wrote on Twitter. "No one knows how the day will continue."

If a deal emerges, it won't bring an immediate end to the political limbo following Germany's Sept. 24 election. The country has already broken its post-World War II record for the longest time from an election to the swearing-in of a new government.

Any agreement will be put to a ballot of the Social Democrats' more than 460,000 members, a process that will take a few weeks. Many members are skeptical after the party's disastrous election result, which followed four years of a "grand coalition" with the party serving as junior partner to Merkel's conservatives.

Failure to reach an agreement, or a rejection by Social Democrat members, would leave a minority government under Merkel or a new election as the only viable options.

Merkel's attempt to put together a government with two smaller parties collapsed in November. Social Democrat leader Martin Schulz, who had previously ruled out renewing the coalition of Germany's biggest parties, then reversed course.