Jason Kenney is defending the government's controversial temporary foreign workers program even as a major fast-food chain freezes its participation and a respected economist casts fresh doubt on the extent of Canada's skills shortage.

In Manitoba on Wednesday, the federal employment minister reiterated that employers who abuse the program could face fraud charges and jail time. The program remains under review and further changes will be announced soon, he added.

"Obviously, in some small numbers, there are cases of abuse, and we don't tolerate those; we intend to crack down on them severely," Kenney said.

"The more important thing is that we prevent abuse in the first place and that's why we've tightened up the rules, and we'll continue to do so."

Kenney's remarks came as McDonald's announced it was putting on hold its participation in the program while a third party conducts an audit on its use of the plan. The fast-food giant has been in hot water for hiring so many temporary foreign workers at some of its Canadian franchises.

Indeed, a vast array of companies and government bodies employ temporary foreign workers, according to data compiled by Kenney's ministry.

There's been a particularly astronomical increase in the number of hotels and restaurants accessing the program under the Conservatives. The initiative was originally designed to address shortages of skilled workers, not menial labour.

Jeffrey Reitz, an immigration expert at the University of Toronto, warned that opening Canada's doors to temporary foreign workers with few skills will lead to a host of other problems.

"The experience in every country has been that temporary foreign workers at low skill levels, when their visas expire, may decide to stay on without authorization," he said.

"It's very common, and the government has simply ignored all that international experience .... they have no way to monitor whether those people actually leave the country."

Don Drummond, an economist who wrote a report for the government five years ago on labour markets, said there's no hard data to back up Ottawa's insistence that a persistent skills shortage justifies the use of such workers.

"It's all anecdotal evidence," Drummond, approached in 2008 by provincial and federal labour ministers to compile data, said in an interview.

"They keep saying we don't have any tradespeople, but in the latest data for every available construction job in Canada, there's eight unemployed construction workers. Even when you look at the data over the summer -- a busy time in construction -- overwhelmingly, there are unemployed people in construction as opposed to job vacancies."

Drummond said he provided the government with 69 recommendations aimed at improving the quality of the information on Canada's labour markets. Most of them have been gathering dust, he said.

Kenney, who sat down with Drummond last fall to discuss those wayward recommendations, has acknowledged the government needs to do a better job compiling meaningful labour market data.

"We are working with Stats Canada on ways to get more robust labour market information and are also working with provinces," he said recently.

The minister has also hinted that he's mulling over restrictions that would make it more difficult for fast-food restaurants in urban areas to apply for temporary foreign workers amid a spate of alleged abuses of the program by restaurant owners.

But Kenney largely scoffed Wednesday at suggestions from "academics" who proposed alternatives to the temporary foreign workers program -- including providing such workers with a path to permanent residence to cut down on potential abuses.

The heads of the Canadian Federation of Independent Business and the Saskatchewan Federation of Labour have suggested changes to the permanent immigration system that could lessen the need for temporary foreign workers.

Kenney said the government is already expanding opportunities for temporary foreign workers to become permanent residents, but added some of them don't want to remain in Canada.

"I mean I know Canada's great, and we often assume everyone who visits us wants to stay permanently, but the truth is that the top-source countries for folks coming here on work permits are the United States, the United Kingdom, France, and Australia," he said.

"A lawyer who comes to work in Winnipeg to do a merger agreement for six months is, believe it or not, a temporary foreign worker and probably doesn't necessarily want to stay forever."