Controversial Liberal senator Cory Bernardi, who has called the United Nations an "unelected and unaccountable body", will represent Australia during a three-month secondment with the global organisation.

Senator Bernardi will be joined in the bipartisan annual delegation by Tasmanian Labor senator Lisa Singh. The trip usually commences in early September.

While in New York, the parliamentary delegates will work with the established Australian Mission to the United Nations, and attend meetings, speaking engagements and other official functions.

Senator Bernardi is a longstanding critic of the UN. In a 2010 speech to the Senate, he lamented that the then-Labor government's climate change agenda was "outsourcing aspects of our national sovereignty to unaccountable foreign organisations like the United Nations".