After 24 hours of outraged reaction from Conservative MPs and some backpedalling by Liberals, McGuinty issued an apology and said he was stepping down from his critic role.
"As member of Parliament for Ottawa South, I would like to unreservedly and unequivocally apologize for comments which I made with respect to parliamentary colleagues from the province of Alberta," McGuinty said in a statement Wednesday afternoon.
"My words in no way reflect the views of my party or leader, and I offer my apology to them as well as my colleagues from Alberta.
"I hold all parliamentarians in high esteem, and I regret my choice of words, as I can understand the offence they have caused," McGuinty said.
The Liberals said Montreal MP Marc Garneau would handle natural resource critic duties on an interim basis in addition to his role as House leader.
'Go back to Alberta'
McGuinty was quoted by Sun Media as saying the MPs "really should go back to Alberta" and run for the Alberta legislature or municipal office in areas "deeply affected by the oilsands business" if they weren't willing to adopt a national outlook.
"They are national legislators with a national responsibility, but they come across as very, very small-P provincial individuals who are jealously guarding one industrial sector, picking the fossil fuel business and the oilsands business specifically, as one that they're going to fight to the death for," the Sun quoted an angry McGuinty as saying Tuesday following a meeting of the natural resources committee into energy innovation.
The reaction from Conservatives was swift.
Joan Crockatt, who is in a tight race with a Liberal candidate in Monday's byelection in Calgary Centre, quickly issued a news release invoking former Liberal prime minister Pierre Trudeau's energy policy from more than three decades ago.
"This anti-Alberta prejudice is the same the Liberals had when they brought in the disastrous National Energy Policy in the 1980s that did tremendous damage to our economy and cost Albertans billions of dollars," she said.
The Conservative outrage continued Wednesday, with several MPs rising in the House of Commons to denounce McGuinty's comments, including Prime Minister Stephen Harper.
"I find it shameful, I guess not surprising, but shameful that 30 years after the National Energy Program these anti-Alberta attitudes are so close to the surface in the Liberal Party," Harper said.
Calgary Southeast MP Jason Kenney, the immigration minister, said before question period the remarks were "deeply offensive" as he called on McGuinty to apologize.
"It's totally inappropriate and, frankly, arrogant for a parliamentarian to tell elected colleagues they don’t belong here, that they shouldn't be representing their constituents, that they shouldn't be advocating for economic growth in one of the key growth industries in the Canadian economy," Kenney said after his party's weekly caucus meeting.
"I would remind Mr. McGuinty that three-quarters of Canada's petroleum production actually happens in Alberta, that Alberta's energy industry is Canada's energy industry and that industry is responsible for almost 20 per cent of our country's gross domestic product. The entire Canadian energy industry is creating hundreds of thousands of jobs across the country."
Comments not 'helpful'
Interim Liberal leader Bob Rae said earlier Wednesday that McGuinty's comments weren't "helpful" and made it clear he expected an apology, but said the comments likely came from "exasperaton" with Conservative members on the natural resources committee.
"I think the way he expressed himself was unfortunate."
Later, on CBC News Network's Power & Politics, Rae said McGuinty's views as reported don't reflect those of the party, and said the Liberals back Alberta Premier Alison Redford's call for a national energy strategy.
Justin Trudeau, who is running to be the next Liberal leader and who has already taken pains to distance himself from his father's legacy in the West, was asked about McGuinty's remarks during a stop in Edmonton on Tuesday, but wouldn't comment on them directly.
"My entire campaign has been about bringing people together, about not pitting region against region and about being a strong representative and a voice that says the same thing in Chicoutimi as we say in downtown Calgary as I'll say in Toronto as I'll say in B.C.," Trudeau said.