German Chancellor Angela Merkel's coalition defeated an election-year opposition bid Thursday to set a quota for female board members in a vote that exposed a party rift and forced her to give ground.
The Bundestag lower house of parliament rejected the motion, which called for the gradual introduction of a 40-percent binding quota for women in supervisory and management boards of large companies from 2023.
After an emotional debate, 320 lawmakers voted 'no', while 277 voted in favour, with one abstention.
Five months ahead of elections, opposition deputies had forced the vote which earlier in the week backed Merkel into a corner after some of her allies threatened to break ranks and help pass the motion.
Urging parliament's support, Frank-Walter Steinmeier, a leading member of the centre-left Social Democrats, said if progress continued at the current rate "it will take until the middle of the century until we have occupied 40 percent of supervisory board seats with women".
"That is decidedly too late," he said.
Merkel, 58, the first female leader of Europe's top economy and often cited as the world's most powerful woman, has opposed the introduction of compulsory quotas for women in the boardroom.
But her Labour Minister Ursula von der Leyen has long been a staunch backer of the move and initially had not made it clear whether she would toe the party's line in Thursday's ballot.
At what was described by a senior party member as an "intensive discussion", leaders of Merkel's Christian Democratic Union (CDU) agreed a compromise Monday to include in its manifesto from 2020 a 30-percent female quota in supervisory boards.
The move marked a change of course just four months after CDU members backed a flexible approach for companies to voluntarily decide on quotas for women in the boardroom at their party congress.
Merkel has appeared to play down her party's internal squabbling.
"Issues of equal treatment, family policy, also the childcare benefit, such things are always discussed by us in the CDU with a great deal of passion," Merkel told Thursday's Bild mass circulation daily.
"And one learns, not all women think alike," she added.
Her spokesman told reporters Wednesday that Merkel's stance in the debate remained unchanged -- there must be more women in top business posts.
The compromise succeeded in uniting the CDU, including von der Leyen who is also a deputy leader of the centre-right party, to reject the opposition's draft legislation.
But von der Leyen has faced stiff criticism from within her own party, with Christean Wagner telling the daily Frankfurter Allgemeine Zeitung that the minister could not afford another such incident.
"Otherwise she'll endanger the election victory of the Union," he was quoted as saying, referring to Merkel's conservatives.
Lawmakers traded blows during the debate. Steinmeier, who heads the SPD's parliamentary group, accused the conservatives of "hypocrisy" by planning to include the female quota in their manifesto but rejecting a bill.
Family Minister Kristina Schroeder said the opposition move was "sanctimonious" while CDU politician Gerda Hasselfeldt blasted it as an "election manoeuvre".
"Your goal is not to basically improve the situation of women in leading functions but... to drive a wedge into the coalition... and that won't succeed," she said.
News website Spiegel Online said the debate in recent days had been "more disastrous" than the outcome.
The conservatives "are selling their buckling as a success while nothing better occurs to the opposition than tactical games or clumsy bluster. You don't win female voters back this way," it commented.
Die Zeit weekly pointed out in its online edition that the CDU's business wing was critical of the quota move. "With the vote by its MPs, the debate for the Union (conservatives) however is not yet over," it said.
Merkel's junior coalition partners, the pro-business Free Democratic Party, made it clear that, unlike their CDU allies, they would continue to oppose a female quota after the September 22 election.
Women made up four percent of management board membership among the 200 biggest German companies in 2012, according to a study by the DIW economic research institute.