FDP leader Guido Westerwelle on Sunday evening signalled on public television that his party might drop its opposition to working with the two other parties in Germany's most populous state.
"The FDP is now in the opposition, but if things have changed, because the SPD and the Greens or the CDU and Greens are rethinking matters, then they know where to reach our state party chairman," Westerwelle, who is also German foreign minister, said.
Westerwelle's statements signal a change of heart for the FDP, which has in recent years traditionally partnered with Angela Merkel's conservative Christian Democrats (CDU).
FDP parliamentary group leader Birgit Homburger told daily Bild that the party supported the option including her party, the SPD, and the Greens – whose party colours yellow are red, and green respectively.
“Coalitions orient themselves on substance,” she told the paper. “Naturally coalitions are fundamentally possible with the SPD.”
“In the future we will also review statements about probable coalitions,” she added, urging FDP supporters not to overestimate the value of a new partnership.
“It's not a question of principle,” she told Bild.
Last week the SPD and the Greens abandoned coalition talks with the hard-line socialist Left party, which meant that a “grand coalition” including the SPD and the CDU was likely. But a deal between the two parties could be hindered by the fact both won an equal number of seats in the May 9 election.
At the moment, the head of the CDU in North Rhine-Westphalia, Jürgen Rüttgers, is demanding to remain state premier in a grand coalition, even though his party's results were considered a bruising defeat and a de facto victory for the SPD.
Meanwhile on Monday SPD leadership welcomed the FDP's new willingness to consider the “traffic light coalition” in the state.
“It's absurd when they refuse talks with other democratic parties after an election,” SPD parliamentary group leader Frank-Walter Steinmeier told daily Der Tagesspiegel. “It's good that the FDP seems to have seen this,” he said.
Now it is up to the SPD and the Greens to make an official offer of negotiations to the FDP, he said.