After taking on the Western Premiers about the oil sands and Dutch disease, Thomas Mulcair and the NDP are now up 1.6 points and lead all the major parties with 34.5% support.
The blog ThreeHundredEight.com compiled survey data from several leading polling firms. The Conservative party was second with 34.1% support. The rest of the parties, Liberals, Greens and Bloc Quebecois, were all down.
The Leader of the Opposition claimed that the resource industry was driving up the cost of the Canadian dollar and success out West was coming at the expense of the Ontario manufacturing sector.
And the rhetoric largely played itself out in the polls: the NDP was up in Ontario and down in Alberta:
The largest amount of variation between April and May took place in Alberta, where the Conservatives picked up four points to hit 60%. The New Democrats, meanwhile, were down 1.4 points to 19.1% and the Liberals were down 3.5 points to 12.7%. The Greens were up 1.4 points to 6.1%.
A more consequential shift took place in Ontario, where the Conservatives slipped 2.5 points to 35.5%. The New Democrats hit a new high with a 4.6-point gain to 33.6% support, the narrowest gap between the Conservatives and the second place party since November 2010.
Table is from ThreeHundredEight.com