BERKLEY, Mich. (AP) — A federal prosecutor who quit his job to launch an independent candidacy for Michigan attorney general says he doesn’t have enough signatures to get on the ballot.

But Chris Graveline apparently isn’t giving up. He says on Facebook that a federal lawsuit is in the works. He says, “Every good lawyer has a plan B.”

Graveline didn’t meet a Thursday deadline to collect 30,000 signatures to run as an independent candidate for attorney general.

He headed the violent crime unit at the U.S. Attorney’s Office in Detroit, prosecuting gang members and drug traffickers.

Graveline had support from Barbara McQuade, his former boss and a University of Michigan law professor. McQuade was U.S. attorney under President Barack Obama.

McQuade says on Twitter she’s now backing Democrat Dana Nessel.