Days after a transgender high school athlete won two California track events, the Trump administration is threatening legal action.

The California Department of Education on Tuesday weighed in on the escalating controversy over transgender athletes in school sports, advising schools to hold the line in the wake of threats from the federal government.

Trump threatened to fine California after a trans athlete shared the podium at a track meet Saturday under a state rule that allows trans athletes to compete as long as they don’t bump cisgender girls from the medals.