PHOENIX  A federal judge on Wednesday blocked the most controversial parts of Arizona’s immigration enforcement law from going into effect, a ruling that at least temporarily squashed a state policy that had inflamed the national debate over immigration.

Judge Susan Bolton of Federal District Court issued a preliminary injunction against sections of the law, scheduled to take effect on Thursday, that called for police officers to check a person’s immigration status while enforcing other laws and required immigrants to prove that they were authorized to be in the country or risk state charges. She issued the injunction in response to a legal challenge brought against the law by the Obama administration.

A spokesman for Gov. Jan Brewer, a Republican who signed the law and has campaigned on it for election to a full term, said Wednesday that the governor would appeal the injunction on Thursday and ask for a speedy review. Legal experts predicted that the case could end up before the Supreme Court.

The law, designed to seek and deport illegal immigrants in a state that is the principal gateway for illegal border crossers, had provoked intense debate from coast to coast, drawing support in several polls but generating boycotts of the state by major civil rights groups and several cities and towns.