Portland city officials aren't taking Uber's invasion lying down. Instead, they're taking the ride-sharing company to court.

Portland officials today filed an injunctive lawsuit in Multnomah County Circuit Court, asking a judge to order the company to stop operating until City Hall grants Uber permission.

"If Uber thinks there should be no maximum price on what they charge Portlanders, they should make their case to the Portland City Council," City Commissioner Steve Novick says in a statement. "If Uber thinks taxi companies shouldn't have to serve people with disabilities, they should make their case. If Uber thinks taxis should not have to have proper insurance in case of a crash, they should tell us why we should allow that."

Portland transportation director Leah Treat sent Uber a letter this morning, warning of the lawsuit and saying city officials will start impounding drivers' cars.

"The city will be taking appropriate enforcement action against Uber's illegal activities and those of its drivers," Treat writes, "which may include bringing suit against Uber for injunctive and other relief, imposing civil and criminal penalties, impounding illegally operated for-hire vehicles and any other steps deemed necessary and appropriate to protect the public."

Oregon Public Broadcasting first reported the cease-and-desist letter today.

The injunctive lawsuit closely follows the playbook of officials in Nevada, who pushed Uber out of Las Vegas with a court order.

Uber has responded the same way in Portland as in Vegas: It has started an online petition calling on Mayor Charlie Hales to welcome the company.

"This is about more than picking sides," Uber's petition says. "We're here to become part of the fabric of Portland--by helping cut down on drunk driving, serving under-served communities, increasing transit to small business and helping drive the local economy."