Mayor de Block said that the measure did not violate human rights and that it would help integration.
Mr. Yeltsin's aides say the measure does not violate civil rights.
The bill's many Republican opponents say the measure violates free speech rights and will put their party at a disadvantage.
Its Republican opponents say it would put them at a fund-raising disadvantage and that the measure violates free-speech guarantees.
He also said that the measure would not violate the City Charter.
The court held, in a 5-to-2 decision, that the measure violated teachers' First Amendment rights to freedom of speech and religion.
In addition, some liberals argue that the measure would violate the civil rights of the accused.
Civil rights groups argued that the measure would violate rights of free speech and vowed to fight it.
In the U.S. view various measures have violated international law.
But critics say the measure would violate the constitutional right to free speech.