Huawei Technologies Co. Ltd chief legal officer Song Liuping ratcheted up the Chinese tech giant's public relations offensive Wednesday, when he denounced the U.S. government's actions against his company as "not normal" and "trial by legislature."

Song also announced during a press conference in Shenzhen, China, that Huawei had just filed a motion for summary judgment in the Eastern District of Texas. The company is asking a federal judge to declare that the Trump administration's use of a provision in the National Defense Authorization Act to ban Huawei's equipment is unconstitutional.

"This legislation provides Huawei with no opportunity to defend ourselves or provide evidence. … This is 'trial by legislature,' and it is prohibited by the U.S. constitution," Song said. He later argued that Huawei does not pose a security threat and "U.S. politicians are using cybersecurity as an excuse to gain public support for actions that are designed to achieve other goals."

Adams Lee, an international trade lawyer at Harris Bricken in Seattle who represents U.S. and China companies, expressed some skepticism about the merits of Huawei's constitutional argument, at least at this stage in the lawsuit, which was filed in March.

"Speaking as a general observer, any time anyone raises a U.S. constitutional argument, that's usually kind of a Hail Mary type of argument," he said. "If you're using the kitchen sink approach, that's something you throw in to flavor the rest of the arguments you're using. If you're leading with that it doesn't sound like it's a terribly strong argument."

However, Lee, reflecting on the NDAA, added that "people have always complained about China's government actions being a top-down approach and no one's been able to decipher how China's actions are made or who comes up with these decisions. The U.S. is starting to become more like China in that way."

During the press conference, Song also spoke out against the U.S. Commerce Department's May 16 decision to add Huawei and nearly 70 of its affiliates in 26 countries to a trade blacklist. Song said the move could harm more than 3 billion Huawei customers in 170 countries, including 1,200 U.S. companies and residents in rural areas that lack access to affordable broadband networks.

"This will affect tens of thousands of American jobs," he added. "We believe this sets a dangerous precedent. Today it's telecoms and Huawei. Tomorrow it could be your industry, your company."

Read More: