President Donald Trump's ban on transgender military service has been the target of a growing number of lawsuits since he first announced the policy via tweet in late July. But now the controversial move has drawn the attention of the world's highest-grossing law firm.

Latham & Watkins represents the LGBT civil rights group Equality California and several transgender members of the military in a federal lawsuit filed Tuesday in California challenging the constitutionality of Trump's Aug. 25 directive to the heads of the military.

The lawsuit—which lists the president, Defense Secretary Jim Mattis, the chairman of the Joint Chiefs of Staff and the secretaries of each branch of the armed forces as defendants—seeks to “ensure that all qualified Americans have an equal opportunity to serve in the United States military, that transgender individuals are free from arbitrary and invidious discrimination, and that the constitutional rights of transgender individuals to autonomy, privacy, and freedom of expression are respected and protected.”