On Thursday, politicians in Germany's lower house of parliament, the Bundestag, voted to reject the opposition bill 320-277, which would have set a 40 percent quota for women on corporate boards starting in 2023.

The outcome had been expected.

An opposition compromise for a gradual introduction of the quota to start with 20 percent in the year 2018 also failed to win support in the parliament on Thursday.

German Chancellor Angela Merkel has previously advocated proposals for a voluntary effort by business to increase the number of female executives, but the threat of a split in her Christian Democratic Union party forced her this week to reverse her position and commit to a boardroom quota from 2020.

This contradicts a previous CDU party vote on the matter and has angered Merkel's junior coalition partner, the liberal democrat FDP, which strictly opposes the imposition of a binding quota.

The decision to introduce a binding quota has also angered business groups and marked a policy change just four months after CDU members backed a voluntary approach by companies.

Speaking Thursday to the daily newspaper Bild, Merkel played down the debate within her party.

"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 said.

"And one learns not all women think alike," she added.

Ahead of the vote on Thursday, a leading member of the opposition center-left Social Democrats, Frank-Walter Steinmeier, said progress was too slow.

"It will take until the middle of the century until we have 40 percent of supervisory boards occupied by women," Steinmeier said. "That is decidedly too late."

The most prominent advocate for a quota in the German government is Labor Minister Ursula von der Leyen (pictured above with Merkel), who is also a deputy leader of the center-right party. A CDU politician told another German daily newspaper that von der Leyen could not afford to not toe the party line in future.

"Otherwise she'll endanger the election victory of the Union," Christean Wagner, a representative from Hessen, told the daily Frankfurter Allgemeine.

Germans head to the polls for general elections on September 22, with Merkel hoping to win a third term in office.

jr/rg (dpa, AFP)