While junior coalition partners the Free Democrats (FDP) are in favour of full equality in both spheres, the issue is far less appealing to many members of Chancellor Angela Merkel's conservatives.
While the tax issue has supporters and opponents within Merkel's Christian Democratic Union (CDU) and its Bavarian sister party the Christian Social Union (CSU), the question of adoption rights remains deeply unpopular.
Yet in an interview with the Bavarian newspaper Passauer Neue Presse, the FDP Justice Minister Sabine Leutheusser-Schnarrenberger said the government should not wait for the country's Constitutional Court in Karlsruhe to make a ruling on the subject.
She instead pleaded for the government to introduce a right to adopt for homosexual couples, as well as equality in the tax system for same-sex couples, as for husbands and wives.
"Whoever takes on duties should also receive rights," she said, regarding the existing differences.
"We should not wait for a decision by the Constitutional Court. Karlsruhe has recently, repeatedly made clear that civil partnerships should not be discriminated against through the privilege afforded to marriages between husband and wife."
The Court is expected to rule in the next year on a complaint of discrimination. The German tax system practice of "splitting" means that husbands and wives pay their tax on a joint basis, giving rise to big advantages where there is a big difference between salaries. This arrangement does not apply to gay and lesbian couples.
Leutheusser-Schnarrenberger said a bill now being considered should take care of these matters. "We have had registered same-sex partnerships for 10 years now," she said. "This has legal consequences that that the draft bill put before me should regulate."
CSU general secretary Alexander Dobrindt told the Bild am Sonntag newspaper that extending equal tax rights to same-sex couples was "out of the question" and that the privileges for married couples had a "particular value" to his party.
Gerda Hasselfeldt, the CSU parliamentary leader, said her party would never support adoption rights for gay couples - and accused the FDP of using piecemeal tactics to try to gain concessions.
"They have been bringing piecemeal suggestions again and again about equality of civil partnerships with marriage, something that is neither part of the bedrock or aims of the coalition," said Hasselfeldt.
The current draft bill would mean that the word "spouse" would be replaced by "civil partner" in many existing laws such as on foreclosure and debt laws.
Katherina Reiche, state secretary in the environment ministry for the CDU caused a storm last week when talking about her opposition to extending tax privileges to gay couples. She said Germany's future lay “in the hands of families, not in same-sex partnerships.”
And she added that in her opinion, what she called “this demographic development” was “next to the euro crisis, the biggest threat to German prosperity.”
Reiche was soon the target for hefty criticism, accusing her of homophobia and narrow-mindedness.