Prior to that he was a member of the Legislative Assembly of Manitoba from 1995 to 2004, representing the constituency of Turtle Mountain.
He operated a used car dealership for seventeen years, and was for a time an executive member of the Killarney and Area Recreation Committee.
[3] Despite the NDP's landmark election win of 2003, Tweed was again re-elected in Turtle Mountain without difficulty, receiving 3,956 votes against 1,893 for New Democrat Lonnie Patterson.
[4] Following the 2004 election, Tweed was named opposition critic for Western Economic Diversification by Conservative leader Stephen Harper.
In April 2006, Tweed was elected chairperson of House of Commons of Canada's Standing Committee on Transport, Infrastructure and Communities, a post he held until September 25, 2012 when he was elected chairperson of the Standing Committee on Agriculture and Agri-food.