Ahead of next week's general election, the liberal Free Democrats (FDP) declared the Christian Democrats as their preferred coalition partner, ruling out a three-way coalition with the Social Democrats and the Greens.
FDP chairman Westerwelle says he will only team up with Merkel's conservatives
The leader of the opposition Free Democrats, Guido Westerwelle, says his party intends to form a governing coalition with Chancellor Angela Merkel's conservatives. The announcement is intended to end speculation that the Free Democrats might join forces with other political parties after the September 27 election.
Merkel appealed to the FDP to make an official announcement this weekend in favor of a coalition with her conservative Christian Democrats (CDU), but in the same breath praised the achievements of her four-year-old "grand coalition" with the Social Democrats (SPD).
Westerwelle's announcement means a three-way coalition with the SPD and the Greens is no longer an option for his party.
Steinmeier has little chance of beating Merkel without FDP support
"Because the election manifestos of the SPD and Greens call for more taxation of private individuals and businesses, the FDP will not help those parties form a parliamentary majority," he said.
"We want to see an end to the grand coalition," Westerwelle added. "We want to make sure there is no chance for a left-wing government and have made an unequivocal decision to form a coalition with the conservatives."
Steinmeier warns against center-right coalition
Social Democrat candidate Foreign Minister Frank-Walter Steinmeier reacted defiantly to the FDP's rejection of a possible three-way coalition after the election.
The SPD chairman advised the party to wait until after next weekend's election to decide on a coalition partner.
In an interview with the Bild am Sonntag newspaper, Steinmeier said that voters didn't want an alliance that reflected "social coldness".
"The kind of thinking that led us into this crisis cannot provide the way out of the crisis. That's why the FDP and the conservatives cannot be allowed to win."
"I'm campaigning for a strong SPD that steers the next government on a social course."
Steinmeier ruled out a coalition with the far-left Left party for the whole legislative period until 2013. However, he renewed his call for a three-way coalition with the Green party and the FDP.
Political analysts, however, say another grand coalition with the CDU is the SPD's only chance of returning to government.
Surveys continue to see Merkel in the lead
Merkel has made clarion call for a center-right coalition
This week, three voter surveys showed Merkel's conservatives dipping slightly at 35-36 percent support, while the SPD picked up between one and three points over last week to reach 25-26 percent.
Support for the SPD has risen after a relatively strong performance by Steinmeier in a head-to-head television debate with Merkel last Sunday.
The FDP currently have 13-14 percent, which would give Merkel a razor-thin majority to form her desired coalition. The only other politically viable option is thought to be a return of the grand coalition, which has been in power since 2005.
Merkel told journalists on Friday that she was confident her conservatives and the Free Democrats would eke out a victory.
"The polls are very encouraging and will motivate us to keep fighting even harder in the campaign," she said.
Editor: Andreas Illmer