Faced with cuts of between 1.3 percent and 7.9 percent in city funding, several of the city’s top prosecutors are warning that the reductions proposed by Mayor Michael R. Bloomberg would compromise their ability to carry out basic law enforcement functions.

Bronx District Attorney Robert T. Johnson told the City Council’s Public Safety Committee at a hearing last week that the 2.3 percent cut projected for his office could force him to lay off more than 12 percent of his 375 prosecutors.