Former senator Nick Xenophon's claims that his legal work for Chinese telecommunications exempt him from registering on the foreign influence register are wrong, Liberal senator James Paterson has said.

In a blistering speech delivered in the Senate under parliamentary privilege late on Tuesday, Senator Paterson said Mr Xenophon risked a "sad end" to his career of public service by taking on Huawei's cause in Australia, where both the Liberal and Labor parties have banned the Chinese company from the 5G and national broadband rollouts on advice from the security agencies.

Senator James Paterson has criticised former senator Nick Xenophon over his work for Chinese company Huawei. Credit:Alex Ellinghausen

Mr Xenophon told the ABC that he was not required to register as he would not be lobbying MPs to make Huawei's case.

"I have had enough of politicians and they have probably had enough of me," Mr Xenophon said. "There are others within Huawei that do a very good [job talking] to members of Parliament and ministers."