U.S. District Judge Zahid Quraishi on Friday ordered the use of office block ballots for the primary, where candidates are placed together by the office they seek.

Several Democrats are eyeing the Senate seat occupied by Democratic Senator Bob Menendez, including Kim. New Jersey's primaries will be held on June 4.

The preliminary injunction sought to eliminate a so-called county line, which gives local party leaders excessive influence over elections.

Democrats are strongly favored to hold the seat in November. New Jersey has not elected a Republican to the Senate since 1972.

Menendez's seat is up for reelection in November and more than a dozen people have filed to run.

Prosecutors have charged Menendez with taking bribes from New Jersey businessmen to impede law enforcement probes into them, illegally acting as an agent of the Egyptian government and obstruction of justice. Menendez has pleaded not guilty to all the charges.

The senator has faced calls to resign, including from members of his own party, but has resisted.

Democrats and the independents who caucus with them currently hold a narrow 51-49 majority in the Senate.

(Reporting by Kanishka Singh in Washington; Editing by Chizu Nomiyama)

By Kanishka Singh