In an interview with German magazine Stern, the openly-gay Westerwelle, said it was time for Merkel to "decide" on what direction she would take on the issue.

Westerwelle had stepped back from the public light after his party, the Free Democrats (FDP), failed to claim at least 5 percent of votes in Germany's September election, meaning they were unable to earn a place in parliament.

As part of the coalition between the Christian Democratics (CDU) and the FDP, Westerwelle had served as Merkel's vice chancellor from 2009 and 2011. He believes, however, his former colleague can do more on the issue of gay rights.

Despite the FDP's poor showing at the polls, Westerwelle said he hoped "the progress made during our term in government" would be completed in Merkel's third term, "namely the complete legal equality of same-sex partnerships and marriage."

He said Germany had yet to achieve that equality, adding of Merkel: "Now she has to decide."

Issue outstanding

Westerwelle has lived in a civil partnership with Michael Mronz since 2010. German parliament approved a law granting same-sex couples equal tax rights in June 2013, but same-sex marriage is still not recognized.

It loomed as an issue in negotiations over the 'grand coalition' agreed upon between the CDU and the Social Democrats (SPD) in November, but the law remained unchanged.

Merkel's government issued a positive response to the coming out of former Germany football international Thomas Hitzlsperger on January 8.

"We judge footballers by whether they conduct themselves well and with dignity on and off the pitch, and I believe both are true for Mr. Hitzlsperger," government spokesman Steffen Seibert said after the former Aston Villa and Stuttgart midfielder's announcement.

ph/dr (dpa, AP)