OTTAWA—Former New Democrat MP Paul Dewar announced Saturday that he has been diagnosed with cancer.

The news emerged on the second day of the party’s national convention in Ottawa, prompting emotional responses from MPs and staff who had worked for years with the former Parliamentarian from Ottawa-Centre.

“He has served our party, this city with such integrity,” northern Ontario MP Charlie Angus (Timmins) said on the convention stage Saturday.

Quebec MP Hélène Laverdière added that Dewar is a fighter and offered encouragement as he undergoes treatment for a brain tumour that was removed this week.

“He is a man of principle,” she said in French, as hundreds of NDP delegates rose to their feet in a show of support. “He has always done what he will continue to do: put all his talents and personality to the service of people. . . . I know that Paul is a fighter, so I know that he can do it. He can.”

Dewar posted on Facebook Saturday that he went to the hospital for testing on Feb. 5. Days earlier, Dewar said his left arm started hurting after he went skating on Ottawa’s Rideau Canal. He learned that he had a tumour on his brain, and after consulting with medical staff, underwent surgery on Wednesday to have the growth removed.

“While this cancer is devastating news, I am going to pursue the next phase of my treatment with determination, passion and an appreciation for life,” Dewar wrote.

“I am perched by the side of a strong flowing river of love that gives me the courage and inspiration to take on this challenge.

“Every one of us knows someone who has had cancer and each journey is personal. People ask what they can do. If you can, please consider getting involved in something that will help your neighbourhood. Look for the beauty that exists all around us and share it with each other.”

Dewar was first elected to the House of Commons in 2006 and represented his downtown Ottawa riding until 2015, when he was unseated by Liberal candidate Catherine McKenna, who is now the environment minister.