Employment Minister Jason Kenney hinted on Tuesday at what the next set of changes to the Temporary Foreign Worker Program will include, just as Prime Minister Stephen Harper issued his clearest warning yet to employers who abuse the program.

Kenney said he intends to give Service Canada further audit powers as part of the government's ongoing reform of the program, which has come under increased scrutiny following a series of stories by CBC reporting alleged abuses of the program.

New rules that went into effect on Dec. 31, 2013, gave federal officials the power to conduct spot-checks in workplaces to make sure employers are meeting the conditions of the program.

"We have new legislative authority … that came into effect last December that allows Service Canada to go in unannounced to work sites, to pull up their paperwork, to do the interviews and to dig down and see where there may be instances of abuse," Kenney told the House of Commons on Tuesday.

"It's my intention to add further to those audit powers of Service Canada," Kenney said.

The minister said the government has been working on another set of reforms to the program which he will announce "in the next few weeks."

Kenney's comments came while MPs debated an an NDP motion calling for an urgent audit of the program by the auditor general.

The NDP motion also calls for "an immediate moratorium on the stream for lower-skilled occupations, which includes fast food, service and restaurant jobs."

Liberal MP John McCallum asked the AG to audit the program last week.

'A preference' for foreign workers

Tuesday was the second day in a row Conservatives came under fire in the House of Commons from both opposition parties.

Unlike Monday, Harper was in question period today taking some of the heat off Kenney, who was grilled by the New Democrats and the Liberals the day before.

Prime Minister Stephen Harper says the government will not tolerate employers who hire foreign workers when Canadian workers are available for the same job. (Sean Kilpatrick/Canadian Press) "It does appear to be the case that there are some Canadian employers who believe that they can have a preference for temporary foreign workers," Harper said. "This government has been clear: That is absolutely unacceptable and it will not be tolerated."

Today, NDP Leader Tom Mulcair asked "how long has the prime minister known about these blatant abuses?"

Liberal Leader Justin Trudeau asked, "Will the prime minister now commit to significant reductions in the size of this broken program?"

Harper was categorical in his reply saying, "Temporary foreign workers can be used when they are needed, but only when they are needed. They can never be used in place of available and willing Canadian workers."