Force of nature: tributes flow for Labor giant 'Richo'

"We have lost a giant of the Labor party and a remarkable Australian," Prime Minister Anthony Albanese said in a statement.

Mr Richardson played a major role in the factional stability enjoyed for most of the nine years of Bob Hawke's government before he threw his support behind Paul Keating.

In 1983, aged just 33, he became the youngest senator ever elected and stayed in the role until 1994.

Known as the "minister for kneecaps" during his time in the Upper House, Mr Richardson was widely feared as a number-cruncher, fixer and kingmaker. 

He also became an advocate for nature and, as environment minister, fought hard to halt polluting development and save forests including the Daintree.

Environmentalist Bob Brown said he was the engineer of the Hawke government's most significant environmental wins.

"Richo had a rare insight into Australians' love for wildlife and nature and an even rarer ability to harness that devotion into a winning political strategy," Mr Brown said.

His passing was announced on Sydney talkback station 2GB by broadcaster Ben Fordham, who had spoken to Mr Richardson's wife and son, who confirmed he had been struck by a bout of influenza and pneumonia.

"Darcy and Amanda have asked me to share the news with everyone, and sadly, Richo has passed away in the early hours of this morning," Fordham said. 

"This has come as a huge shock to me."

After politics, Mr Richardson worked as a lobbyist, radio talkback host, writer and political commentator with Sky News.

Health battles with chondrosarcoma, a rare form of cancer, dominated his later years.

Opposition Leader Sussan Ley said she was saddened by the loss of the Labor stalwart.

"On behalf of the Liberal Party, I extend my condolences to his family, friends and former colleagues," she said on X.

Labor Minister Tony Burke described Mr Richardson as a force of nature.

"Richo was a full tectonic plate," he said in a statement.

"Dragging the entire landscape with him when he moved."

Former Liberal treasurer Josh Frydenberg called him a "fiercely loyal Labor man who was not afraid to make friends across the political aisle".

"I enjoyed his company and his insights ..." he added.