German Chancellor Angela Merkel will launch a new round of coalition talks on Sunday in a bid to end the country's political stalemate.
More than three months after its election, Germany is still without a new government.
The five-day talks will include Mrs Merkel's Christian Democrats (CDU), her allies the Christian Social Union (CSU), and the Social Democrats (SPD).
Experts say this may be her last chance to form a stable coalition.
The centre-left SPD has governed jointly with the chancellor's centre-right party for eight of the last 12 years. But a historically poor poll result in September saw SPD leader Martin Schulz vow to take the Social Democrats into opposition.
Pressure has mounted on the SPD since November, when Mrs Merkel failed to cobble together a coalition with the liberal FDP and the Greens.
The chancellor must now convince SPD leaders that they have enough common goals to start formal coalition negotiations by March or April.
European Union allies, such as France, who see Germany as a pillar of stability in the bloc will be hoping she succeeds.
Immigration, Europe, tax, and healthcare could all become points of contention.
Within the SPD, socialist voices have argued that reforming the grand coalition would cost the party yet more support. Some claim the SPD has given up its core principles to cling to power with Mrs Merkel.
The chancellor faces similar censure from conservatives, who say she has abandoned traditional values and driven voters towards the far-right Alternative for Germany (AfD), which is now represented in the federal parliament for the first time.
If talks fail, Mrs Merkel could form a less stable minority government with the Greens, with SPD support.
However, she has previously said she would prefer a fresh election to that eventuality, reports BBC.