Many in Berlin fear a fresh round of elections would further frustrate voters and strengthen the position of the far right. Despite the apparent unwillingness to bend on campaign promises, no one wants to be seen as the party that brought down the coalition.

“Understanding and compromise, which must constitute the coalition, are nothing new in the German system of consensus,” wrote Nico Fried in an editorial in the left-leaning Süddeutsche Zeitung. “Politicians who, by all understandable differences, are unable to find a viable compromise on which to build a coalition, will only disgrace themselves in the eyes of the people.”

A sense of accountability to the electorate has held the parties together through four weeks of negotiations that some seasoned lawmakers have described as the most difficult task they have ever undertaken. Negotiators have searched for compromises, even as individual members of the parties took turns sniping at one another for failing to concede on points they considered a condition of their participation.

“The responsibility for the people and the future of our country unites us,” read the opening paragraph of a draft document circulated late Thursday, as the talks entered what was supposed to be their final round.

“Through the outcome of the election, we are faced with the task of building a capable and successful government,” the preliminary agreement read.

Each side brought its own agenda to the table, as well as fears of being punished by voters if they gave up too much on campaign promises. The Free Democrats, for instance, have just returned to Parliament after four years without representation, drawing 10.7 percent of the vote. Before that barren spell, they spent four years as a junior coalition partner in Ms. Merkel’s government, which many in the party see as having cost them seats.

Ms. Merkel herself is under pressure from the right wing of her conservative bloc, especially from the Christian Social Union, which is urging her not to backtrack on a commitment she made last month to limit to 200,000 the number of people allowed to apply for asylum in Germany.