A newly-elected Australian Senator has used his maiden speech to call for his country to leave the “socialist monolithic monster” of the United Nations.

Malcolm Roberts, who is a member of the populist One Nation party, also criticised the idea of man-made global warming and said taxation was far too high.

Speaking in the Australian Senate, Mr Roberts pledged to fight “the establishment”, hailing the “grassroots uprising of the Australian people” that saw him and three other One Nation politicians elected to the Senate.

“All of us, as One Nation senators, are going to say the things that need to be said and do the things that need to be done,” he said.

“We are not worried what the establishment says about us. We are not here for the establishment. We’re here for everyday people.”

Speaking about the United Nations, Mr Roberts called the organisation a “socialist monolithic monster” full of “unelected swill”.

“We need an Aus-exit,” he said. “The people of Australia are desperate to regain our sovereignty. We need to rebuild our nation.”

He also questioned modern climate science, saying that global temperatures have not been rising since 1995.

“Temperatures are now cooler than 130 years ago and this is the reverse of what we’re blatantly told by the Bureau of Meteorology that has manipulated cooling trends into false warming trends.”

“I have used freedom-of-information requests, correspondence and reports from the heads of the CSIRO, the Bureau of Meteorology, the UN [and] universities to show there is no data proving human use of hydro-carbon fuels effects climate. None.

“Yet the core climate claim is that carbon dioxide from our human activity will one day, some day, catastrophically warm our planet.”

Mr Roberts also thanked his party leader Pauline Hanson for bringing the party to the point where it had four elected Senators.

“Twenty years ago, Pauline, the establishment ridiculed you. At the same time, they quietly started implementing some of your policies.”

Pauline Hanson founded One Nation in 1997 after leaving the centre-right Liberal Party. The party is described as “right-wing populist” and takes a strongly patriotic line, opposing mass immigration and Islamisation.