TORONTO (Reuters) - Well-wishers including Canada’s prime minister are rallying around Harry Leslie Smith, the ailing nonagenarian who bills himself the “world’s oldest rebel,” after he fell and was hospitalized in Canada this week.

Smith, 95, who rose to fame in 2014 after giving a powerful speech at the UK Labour Party’s convention and documented his fight for social justice in a podcast called “Harry’s Last Stand,” was hospitalized in Belleville, Ontario.

“Harry is in (the emergency department) and not in a good way,” his son John tweeted, taking over his father’s Twitter account on Tuesday. “He asked me to inform you in case things don’t work out. I will keep you posted.”

That prompted thousands of well wishes from Twitter users, under the hashtag #IStandWithHarry, including from Canadian and British politicians and refugee organizations.

“He’s stood #WithRefugees since he first saw them with his own eyes during WWII. Now it’s our turn to stand with him,” the United Nations High Commissioner for Refugees tweeted Wednesday.

Canadian Prime Minister Justin Trudeau tweeted that “we’re pulling for you,” while UK Labour leader Jeremy Corbyn wrote “we need him to get well soon ... our movement, needs him.”

The outpouring was “humbling,” son John Smith told Reuters. Smith has been posting regular updates on his father’s Twitter account, @harryslaststand.

Smith survived Britain’s post-World War One recession in abject poverty and spent much of his later life campaigning to ensure others did not experience the same, his son said. Besides healthcare and refugee advocacy, Smith has written several books since turning 87.

On Wednesday, Smith was being moved to an intensive care unit with low blood pressure and suspected pneumonia, his son said. “He’s in critical condition, but not acute critical condition.”

Until his fall, Smith was in the middle of a tour of refugee hotspots around the world. If he recuperates, his son said, the plan is to visit the Canada-U.S. border, where thousands of asylum seekers have been walking across the border to file refugee claims.

“I don’t know Harry personally but I feel as if a friend is ill tonight. Harry, you are an inspiration and a light when the world seems dark,” Twitter user @Hawkonaridge said.