Members of German Chancellor Angela Merkel’s conservative party, the Christian Democratic Union, have called for gay couples in civil unions to have┬áthe same tax breaks as married couples.

A group of thirteen members of Ms Merkel’s Christian Democrat party MPs said the move was “only consistent” with other moves towards equality.

The party controls 193 of the 620 seats in the Bundestag, operating a majority through a coalition agreement with the Free Democratic Party, FDP, and the Christian Social Union of Bavaria, CSU.

Kristina Schroeder, the CDU families minister, told German media it was “the right time” to equalise tax treatment of gay and straight couples in registered relationships.

Gay couples in Germany have been able to enter registered life partnerships since 2001 but they have never conferred similar tax benefits to straight marriages.

Earlier this week, a constitutional court ruled that public sector employees in gay registered relationships should not be denied the wage supplements given as family allowances to married couples if they have the same custody rights as married couples.

German CDU MPs issued a statement saying the party should adopt a position in favour of equal tax laws for gay and straight relationships rather than continually react to court decisions, The Local reported.

They said: “We want to recognize that life partners with a registered partnership have set up a framework for a long-term relationship based on mutual trust and affection.”

Registered partners, they argued, have the same “mutual income obligations and duties to each other” as straight married couples, so ought to enjoy the same tax benefits.

The group will put the proposal to the CDU after the parliamentary summer break.

Although the FDP is in favour of equal tax laws, Gerda Hasselfeldt, head of the CSU’s parliamentary group said she was “extremely sceptical”, AP reports.

She said: “Marriage between a man and a woman has special protection because it is fundamentally directed at the propagation of life. That is not the case in homosexual relationships.”