On July 1, 2015, the federal government stopped charging the GST on tampons, sanitary pads and menstrual cups, a change that traced directly to a motion Irene Mathyssen had pushed through the House of Commons that spring. Mathyssen, who represented London-Fanshawe in Ottawa for 13 years after five earlier years at Queen's Park, died October 12, 2026, in London, Ontario. She was 75.

Before entering politics, Mathyssen worked as a schoolteacher in the London area. She was elected to Queen's Park in 1990 as the New Democratic member for Middlesex, and Premier Bob Rae's government put her to work quickly: she served as government whip, then as parliamentary assistant to the environment minister, and finally as a minister without portfolio from October 1994 until the government's defeat the following June, according to the Legislative Assembly of Ontario. Progressive Conservative Bruce Smith unseated her in the 1995 election.

Mathyssen did not stay out of office long. In January 2006 she won the federal riding of London-Fanshawe for the NDP, a seat she went on to hold through three re-elections. In Ottawa she chaired the Standing Committee on Status of Women, later served as vice-chair of the Standing Committee on Veterans Affairs, and spent two years as the NDP's deputy whip, according to the House of Commons.

She used the seat to fight for London's working people. When Caterpillar locked out the 450 workers at its Electro-Motive diesel-locomotive plant in London and demanded wage cuts of more than 50 percent, Mathyssen carried their petition to the Commons floor, telling the House the company was posting soaring profits even as it squeezed the workforce it had locked out, according to the official House of Commons record. She presented that petition on February 2, 2012, one day before Caterpillar announced it was closing the plant for good.

Her most lasting legislative win reached beyond London. Mathyssen spent years pressing to remove the GST from feminine hygiene products, and when the government finally acted in 2015, she credited the women who had organized behind the campaign. "This is a victory for all women," she said. "It shows what a group of determined women and citizens can do. The women who made this an issue, their voices have finally been heard," according to CBC News.

Mathyssen announced in August 2018 that she would not seek a fifth term, saying the job "takes a big chunk out of you" and that she wanted to give someone with fresh energy a chance to serve. She did not leave the riding behind. When she stepped down in 2019, her daughter, Lindsay Mathyssen, won London-Fanshawe for the NDP and took up the same seat.

Mathyssen died at her home in London, surrounded by family, including her husband, Keith, and daughter, Lindsay, according to CBC News. Family friend Nadine Abi Raad remembered her as "a fierce advocate for human rights, for education, for health care, for veterans," adding that she was "very loved, very well regarded and respected." Lindsay Mathyssen said of her mother, "She was someone I looked up to, someone who helped guide me through life."

Mathyssen's name is written into the tax code she helped change: Canadians have not paid GST on tampons or pads since the summer she pushed that motion through the Commons. The London-Fanshawe riding she represented for 13 years is still held by her own daughter, and the Status of Women and Veterans Affairs committees she once led in Ottawa carry forward the nearly 18 years of elected work she built from a London classroom, through Queen's Park, and on to Parliament Hill.