National Public Radio (NPR) and three Colorado public radio stations filed suit against US President Donald Trump’s administration on Tuesday, challenging the legality of an executive order that called for a cessation of federal funding to NPR and the Public Broadcasting Service (PBS).

The order, titled “Ending Taxpayer Subsidization of Biased Media,” directs the Corporation for Public Broadcasting (CPB) to end its direct and indirect funding of the public media outlets. The CPB was created through the Public Broadcasting Act of 1967, and its purpose has been to distribute federal funding to local public radio stations and to act as a barrier between partisan politics and public media content. The order asserts that the CPB has failed its mission and that “which viewpoints NPR and PBS promote does not matter. What does matter is that neither entity presents a fair, accurate, or unbiased portrayal of current events to taxpaying citizens.”

NPR and the local stations claim the order violates the fundamental principles of the First Amendment and argue that the true purpose of the action is vindictive. Plaintiffs claim President Trump views NPR negatively and reference his “antipathy toward NPR’s news coverage and editorial choices.” They argue:

[T]he Order aims to punish NPR for the content of news and other programming the President dislikes and chill the free exercise of First Amendment rights by NPR and individual public radio stations across the country. The Order is textbook retaliation and viewpoint-based discrimination in violation of the First Amendment, and it interferes with NPR’s and the Local Member Stations’ freedom of expressive association and editorial discretion. This is an “egregious form of content discrimination,” an assault on the First Amendment that is “all the more blatant.”

In addition to violations of the First Amendment, the plaintiffs also claim the order violates due process rights, separation of powers principles, and the Spending Clause of the Constitution. The suit further states that the order contradicts congressional intent and that the Public Broadcasting Act established a structure maintained through the creation of the CPB that protected public reporters from governmental interference.

The executive order and suit follow a previous lawsuit filed against the Trump administration by three members of the CPB board whom President Trump attempted to fire on April 28. The board members challenged President Trump’s ability to fire them because the CPB is not a federal agency, and his interference would go against congressional intent by allowing the CPB to be influenced by governmental partisan politics. That lawsuit is still pending.