PHOENIX (CN) – An Arizona attorney sued the state and Coconino County in federal court this week, challenging a state law requiring government contractors to agree not to boycott Israel or work with businesses that do.

Mikkel Jordahl, a sole practitioner who gives advice in the Coconino County Jail, called the 2016 state law unconstitutional. It requires that any company that contracts with a government in Arizona submit written certification that it is not boycotting Israel and that no subcontractors or affiliates do. Jordahl is represented by ACLU attorneys in Arizona and New York; the ACLU is representing a teacher in a similar case in Kansas.

Coconino County, whose seat is Flagstaff, includes the Grand Canyon and Sedona, in North Central Arizona. The immense county has an area of 18,661 square miles.

“The First Amendment squarely protects the right to participate in political boycotts. The government cannot use its financial leverage over state contracts to prevent people from exercising their constitutional rights,” ACLU attorney Brian Hauss, of the New York office, said in a statement.

Jordahl, who lived in Israel briefly as a child and has long sided with Palestinians in the conflict there, signed the agreement in 2016 but has held off signing in 2017, according to the lawsuit.

He says the law chills individual expression and association, though Jordahl understands that it applies only to his law firm and not his personal actions, because he fears his vocal advocacy for Israel boycotts will lead to suspicion about his firm’s compliance.

Jordahl wants to boycott Israel via his law firm, Mikkel (Mik) Jordahl P.C., and use the firm to provide legal support to other organizations engaged in boycotts and related political expression, but the law’s certification requirement prevents it.

“Whatever your stance on the boycott issue, everyone has a right to express their opinions on it and act accordingly. The state has no right to tell private companies how to act when it has nothing to do with state business,” Jordahl said.

The state law is unconstitutional because it compels and restricts political speech, restricts political association and discriminates against protected expression based on its content, according to the ACLU.

Jordahl asks the court to strike down the law as unconstitutional, and enjoin its enforcement.

A spokesman for lead defendant Attorney General Mark Brnovich did not immediately respond to a request for comment. The other defendants are Coconino County, its sheriff and board of supervisors, and the county treasurer.

In the Kansas case, to which the state has not yet responded, the ACLU represents a high school teacher who cannot train other teachers because she won’t sign an anti-boycott pledge.

The ACLU also opposes a bill pending in Congress that would make it a felony to support some boycotts of companies doing business in Israel.

Jordahl’s lead attorneys are Kathleen Brody in Phoenix, and Brain Hauss in New York City, both with the ACLU.