BELLEVILLE, Ont. - A prominent anti-poverty activist who has authored several books on the Great Depression, the Second Word War and postwar austerity is critically ill in an eastern Ontario hospital.

The family of Harry Leslie Smith says that the 95-year-old has been in intensive care in Belleville, Ont., after a fall.

Smith, who lived through the Great Depression and fought in the British air force during the Second World War, has been a lifelong advocate for the poor.

News of his ill health has prompted an outpouring of support, including well wishes from Prime Minister Justin Trudeau.

Smith has written several books, is known for his columns in British newspapers, and has nearly 250,000 followers on Twitter.

His son John has taken over Smith's Twitter account and says his father expressed his appreciation for the support he's received.