A lawsuit filed Monday against Columbia University pro-Palestinian student groups and several of their leaders “has been in the works for well over a year,” according to a lawyer involved in the case.

A pro-Palestinian student protester at Columbia University, who is in the country on a green card visa, sued the Trump administration to stop federal immigration authorities from deporting her. After the State Department revoked Yunseo Chung’s student visa and permanent residency status earlier this month,

The university sanctions demonstrators involved in pro-Palestinian protests last spring while the arrest of organizer Mahmoud Khalil has become a flashpoint on the rights of legal U.S. residents and free speech.