German Chancellor Angela Merkel has opened the door to a free vote in parliament on legalizing same-sex marriage, after signaling a shift in her party's position on it.
Mrs. Merkel surprised the German media by saying she favored a "decision of conscience" on gay marriage.
Her conservative Christian Democrats (CDU) have previously opposed it - unlike the rival Social Democrats (SPD), Free Democrats (FDP) and Greens.
Some MPs want a vote on it this week.
It is not yet clear whether the vote will happen before parliament's summer break, as Mrs. Merkel does not want opponents to score political points from it.
Mrs. Merkel's comments sparked intense debate on social media, and the hashtag #Ehefüralle (marriage for all) is trending on Twitter.
Many of Germany's EU partners have legalized gay marriage, notably the Netherlands, Belgium, France, Spain and the UK.
German Chancellor Angela Merkel during the Brigitte event in Berlin, 26 Jun 17Image copyrightEPA
Chancellor Merkel said same-sex marriage was an issue currently preoccupying the CDU
"I'd like to steer the discussion more in the direction of a decision of conscience," Mrs. Merkel said in a Berlin debate organized by the magazine Brigitte.
She said same-sex marriage was "a really personal matter", so she wanted the CDU and its Bavarian allies, the CSU, "to react differently to this question". It should not be politicized, she stressed.
Reports say the CDU leadership spent an hour and a half discussing the issue on Sunday night while preparing its manifesto ahead of Germany's 24 September parliamentary election.
The opposition parties have set agreement on same-sex marriage as a condition for joining a coalition after the election. Germany is currently governed by a CDU-SPD coalition.
A Twitter message from MPs in the SPD Bundestag (lower house) group said: "Vote now! We say Yes to marriage for all".
Tweet by SPD politician Martin Habersaat: "Vote now! We say Yes to marriage for all"
Germany has civil partnerships but the CDU has opposed gay marriage, in order to keep its most conservative supporters loyal and to avoid friction with the CSU, which champions traditional families.
In the 2013 election campaign, Mrs. Merkel had expressed reservations about gay marriage, saying: "I'm not sure, as far as the children's welfare is concerned."
But in the interview on Monday she described visiting a lesbian couple in her constituency, who are foster parents to eight children. If the state entrusts children to the care of such a couple, she said, "I can no longer argue so simply on the basis of children's welfare".