Nine former FBI agents and intelligence personnel sued the Trump administration Thursday, alleging they were unlawfully fired for working on the investigation into President Trump's handling of classified documents .

Why it matters: The agents' bid to regain their jobs adds to a growing number of legal challenges accusing the Trump administration of retaliating against FBI personnel who investigated the president.

Driving the news: "Plaintiffs were unlawfully terminated not for any cause or any legitimate reason, but only to satisfy the President's personal vendetta," the 70-page lawsuit says.

"As a result of their unlawful and hasty firings, Plaintiffs' investigations were not properly transferred to other FBI Special Agents or Analysts. The impact of these heedless actions on America's national security is immeasurable."

All nine plaintiffs are seeking their jobs back.…