US politicians turned up the heat on Huawei, urging Google to end its relationship with the company on the grounds the Chinese vendor poses a risk to national security.

In a letter to Google CEO Sundar Pichai, a group of five Senators and Representatives noted the US intelligence community’s concerns about Huawei and blasted Google’s decision to continue working with the company even after ending a partnership with the US military. Google in January teamed up with Huawei to work on RCS messaging, but recently declined to renew a contract with the Pentagon to develop artificial intelligence used for drone strikes.

“While we regret that Google did not want to continue a long and fruitful tradition of collaboration between the military and technology companies, we are even more disappointed that Google apparently is more willing to support the Chinese Communist Party than the US military.”

In the letter, the group also warned the US government, which is already considering a number of actions to ban the use of equipment from Huawei and other Chinese telecom companies, “will likely take further [defensive] measures” in the coming months.

Huawei vehemently denied allegations its equipment is used for spying.

The letter is the second Google has received from politicians questioning its relationship with Huawei in recent weeks. Senator Mark Warner wrote to Google parent Alphabet earlier this month asking for more information about its data sharing agreements with Chinese vendors.

Such political disapproval proved successful in the past: earlier this year, AT&T and Verizon backed away from deals to carry Huawei products in the face of political pressure.

Huawei is also battling security concerns in Australia, as the government there decides whether or not to shut the company out of the market for 5G equipment.