While all three major party leaders are more popular than the parties they lead, one — the NDP’s Tom Mulcair — is a clear frontrunner, and his approval rating is translating into support for his party.

“In my experience the approval ratings … often signal how the party will do in voting intention in the future,” said Frank Graves of EKOS Research.

According to EKOS polling data, Mulcair’s personal popularity has risen gradually in tandem with voting intention for the NDP since February. Mulcair, who now polls well over 60 per cent, has been the most popular party leader since the beginning of last winter, and the party he leads now sits in first place among decided voters.

“The most interesting thing about Mulcair is how long his approval numbers were high and vote intention was very low,” said Graves. “Mulcair has the loosest connection between his approval and vote intention, (but) voter intention seems to be coming into closer coherence.”

Liberal Leader Justin Trudeau’s numbers have fizzled in recent months; his own approval rating has fallen from 55 per cent to 47 per cent since February 10, and the Liberals have slipped from first — neck-and-neck with the Conservatives — to third place.

“The most recent decline in approval numbers mirrors the post-March decline in Liberal fortunes,” said Graves. “Broadly speaking, there is a correlation between the curves.”

Stephen Harper, burdened by incumbency, has the lowest approval rating of the three major party leaders. His approval rating has fallen slightly since February, while his party has likewise dipped to second place.

“As his approval ratings are going down, so are party fortunes,” Graves said. With the federal election approaching, he added, “those numbers going down right now are really a challenging problem” for the Conservatives.