A federal judge in Seattle says a lawsuit challenging the public defense systems in the cities of Mount Vernon and Burlington can proceed. Judge Robert Lasnik also granted the case class-action status Thursday.

The American Civil Liberties Union alleges that two part-time attorneys contracted by the cities fielded more than 2,100 cases in 2010. That's although Washington state Bar Association guidelines specify full-time public defenders shouldn't surpass 400 cases a year. The lawsuit alleges the cities fail to provide adequate resources to the public defender system.

In his ruling, Lasnik wrote that the evidence at this stage could support a finding that poor defendants in the two cities "are deprived of counsel at critical stages of the prosecution."

A Seattle lawyer working for the cities, Andrew Cooley, did not immediately return an email seeking comment late Thursday.