KALRSRUHE, Germany (Reuters) - The German government may be forced to abolish a 150 euros (108.46 pounds) a month payment for parents looking after a child at home after the country's Constitutional Court signalled on Tuesday that it may be illegal.
If the court rules against the benefit in a decision expected later this year, it could expose strains between the three parties in Chancellor Angela Merkel's ruling coalition.
Introduced by Merkel's previous government, the benefit was championed by Bavaria's Christian Social Union (CSU), sister party to her conservatives, but opposed by many from the more left-wing Social Democrats (SPD) with which the two have been in an uneasy coalition since 2013.
The case against the "stove bonus", claimed by about 400,000 parents whose young children do not attend kindergarten, was brought by the city of Hamburg, which argues that the central government should not grant benefits that perpetuate inequality.
It says the payment is unfair because parents who send their children to kindergarten do not receive a similar direct benefit, although the institutions are subsidised.
Hamburg also says that because poorer families, especially from immigrant backgrounds, are more likely to claim the benefit, it disadvantages their children by denying them an early education in the German language.
The city also argues that as the overwhelming majority of claimants are women, the law may breach equal rights.
Constitutional Court vice-president Ferdinand Kirchhof said on Tuesday the government could only pass a "public welfare" law if it "is needed to ensure equality across the country".
Another judge on the panel that will rule on the case, Gabriele Britz, has said the federal government holds a remit to pass such a law only if there were "significant" differences in living standards, for example in the number of kindergarten places available in various parts of the country.