She was the New Democratic Party (NDP) Member of Parliament (MP) for the Parkdale—High Park electoral district (riding) in Toronto, and was the Official Opposition's Industry Critic.

Bulte came under heavy criticism as she received campaign donations from entertainment companies, which was considered a conflict of interest given she supported stricter copyright laws.

[14] As a member of the Standing Committee on Industry, Science and Technology,[2] Nash was instrumental in stopping the acquisition of MacDonald Dettwiler by U.S.-owned Alliant Techsystems.

As the Member of Parliament representing the largest population of Tibetan refugees in Canada, she helped push for a resolution declaring the Dalai Lama an honorary Canadian citizen, and also personally introduced a motion calling for negotiations between China and Tibet.

[17] She was a parliamentary representative on the 2006 Canadian post-war fact-finding mission to Lebanon that was condemned by the Conservative government for its support for the legalization and decriminalization of Hezbollah in Canada.

[18][19] In the 40th Canadian general election, held on October 14, 2008, she was defeated by Gerard Kennedy, the Liberal candidate who formerly represented the electoral district at the provincial level.

[22] On January 15, 2010, it was announced on the Parkdale—High Park NDP website that Nash would be running for the nomination to be the electoral district association's candidate in the 41st Canadian general election.

[27] Jack Layton, in his role as Leader of Her Majesty's Loyal Opposition during the 41st Canadian Parliament, appointed Nash as the Finance Critic in his Shadow Cabinet on May 26, 2011.

[28] When she became an MP again, she did not re-offer to run for president, and Brian Topp was acclaimed as her replacement at the federal NDP's Vancouver bi-annual convention on June 18, 2011.

[35] Nash ran for another term in the 2015 federal election, but lost her seat to Arif Virani when the Liberal Party swept all 25 ridings in Toronto, including Parkdale—High Park.

Nash is a decorated political and social commentator featured in The Globe and Mail,[36] The Toronto Star,[37] The Hill Times, The Conversation,[38] Policy Options,[39] Rabble,[40] The Lawyers Daily,[41] and the Huffington Post.

[44] In spring 2020 Nash was presented with an Honorary Doctorate of Law from Brock University, recognized as a long-time advocate for labour, human rights, gender equality and democratic engagement.

She was the recipient of two environmental awards from the Sierra Club of Canada and she helped create the NDP Green Car Strategy with Greenpeace and the Canadian Auto Workers.

[48][49] The YWCA also recognized her contributions to advancing the women's causes in politics, through her involvement with the founding of Equal Voice and becoming an elected member of the House of Commons.

[48] In December 2022, Nash was invested into the Order of Canada in recognition of her advocacy for rights and equality in Canadian politics and the labour movement and for being the first woman in North America to lead union negotiations with a major auto company, breaking barriers in male-dominated sectors.