At least three US Technology companies have joined the Washington State government in a law suit challenging President Donald Trump’s executive order on Immigration.

According to BBC reports, Washington Attorney General Bob Ferguson filed a lawsuit against Trump’s order, which bars legal immigrants and refugees from seven majority-Muslim countries from entering the US and bans Syrian refugees indefinitely.

Microsoft, Amazon and Expedia have since joined the suit promising to avail assistance to see that the executive order is invalidated. Washington State alleges the ban is unconstitutional.

A Microsoft spokesman told BBC that the company is providing information about the effect of the order in order to “be supportive.” They also would “be happy to testify further if needed.”

Further, both Amazon and Expedia are also preparing statements that demonstrate the order’s negative impact on their business.

In a January 30th message to employees, Amazon CEO Jeff Bezos wrote that the company’s legal team “has prepared a declaration of support for the Washington State Attorney General who will be filing suit against the order.”

They are considering other legal options, as well. Expedia hasn’t publicly released its statement.

Other tech company executives, ranging from Tesla CEO Elon Musk to Facebook chief Mark Zuckerberg, have spoken out against the order. Yet only Amazon, Microsoft, and Expedia — all of which are based in the Seattle area in Washington — are in a position to support this particular legal challenge to the immigration ban.