"There are naysayers like Thomas Mulcair's NDP who believe you shouldn't develop our resources to their potential," Oliver told a news conference in Charlottetown.
"Thomas Mulcair says that to help one sector of the economy, you must hurt another sector and kill jobs."
The minister was referring to comments Mulcair made earlier this year which suggested the booming Alberta oil sands have artificially boosted the value of the dollar, hurting the manufacturing sector in Ontario and elsewhere.
"He and the NDP wish to pit one part of the country against another," Oliver said in a statement after day one of a two-day meeting.
"What Thomas Mulcair proposes is reckless and would harm our economy, strand our resources and squander our legacy."
Mulcair has said it would be "senseless" to stop development of the oil sands and he's accused the Conservative government of misrepresenting his views.
Peter Julian, the NDP's natural resources critic, said the Conservative government is resorting to extreme tactics because its members have become alarmed by the party's recent slide in the opinion polls.
"It was a pretty over-the-top statement," said Julian, who was attending the meeting in Charlottetown.
"It reflects a kind of desperate reaction on behalf of the Harper government."
Julian said the polls suggest Canadians are losing confidence in Prime Minister Stephen Harper.
However, he said the Tories are responding by ramping up the rhetoric rather than taking a more reasonable approach to politics. "Those kind of extreme statements don't help bolster the credibility of the Harper government," he said.