Core supporters of Canada's Conservative party are riled up about the budget handed down by Prime Minister Stephen Harper's government and some believe he has strayed from his principles, says a former party strategist.

Tom Flanagan, a professor and former Conservative campaign manager, said Sunday that these supporters are angry that the prime minister authorized a budget that will see his country plunge into an $85 billion deficit over the next five years.

"I am getting more people e-mailing me and commenting to me on this than I ever had by far on any other issue," Flanagan told CTV's Question Period on Sunday.

"I do think there is a problem among Conservative core supporters...I think many of them they don't like the budget and I guess I would believe that Mr. Harper has to do some things to reassure these people that his direction is still fundamentally Conservative."

Tasha Kheiriddin, director of the Fraser Institute's Montreal office, told Question Period that she has been hearing many of the same rumblings from the Conservative community.

"People are upset," she said.

"I think it's definitely a feeling of betrayal in the sense that this budget has very few Conservative principles in it," she added.

"The tax cuts are buried far in the fine print and the spending is very, very lavish to the point where the Liberals didn't even ask for more, so that kind of tells you that Mr. Harper really sold the store on this one."

Kheiriddin suggested Harper has painted himself into a corner by further agreeing to a Liberal request for the government to provide frequent updates to Parliament on the status of the budget.

"Mr. Ignatieff has been very clever in asking for this type of report card every three or four months to see how the government is doing," she said.

"And when he gets a bad report card, as he inevitably will, he will at some point just hold hold it up and say: 'Time for an election, folks. This hasn't worked.' And Mr. Harper will have no leg to stand on because he will have to defend this budget that he put forward that will not have worked."

Flanagan said the prime minister had few options but to go forward as he did when opposition members demanded that he include serious spending in his budget, or he would face the prospect of being voted down in Parliament.

"Given the political jam he was in, which was at least partially his own creation, I don't think he had a whole lot of choice," he said.

In order to win back his Conservative base, the prime minister may choose to woo them through non-financial means, Flanagan said.

"I think this is a done deal, it can't be undone," he said, referring to the contentious budget.

"So that's why I'm suggesting Mr. Harper has to move on to other policies, perhaps outside the budget, things like criminal justice where he can make some accomplishments that the Conservative core supporters will appreciate."