Riding a wave of recent good news, NDP Leader Tom Mulcair brought his party's plan to win the coming election to members of one of Canada's largest unions Friday.

Mulcair addressed more than 1,100 members from the Ontario division of the Canadian Union of Public Employees in Toronto, delivering a speech that focused mainly on attacking the Conservative government and restating the NDP's previously announced election promises, notably its daycare plan.

The party has soared in recent polls, even eclipsing the Conservatives in a survey released this week, just weeks after the provincial NDP's stunning win in Alberta.

"We sense that something monumental is happening across Canada," he said.

"Our path to victory is clear. Only the NDP can defeat Stephen Harper's Conservatives."

Mulcair also briefly commented on Justice Minister Peter MacKay's decision to leave federal politics, which surfaced earlier Friday.

"After nine years of Stephen Harper, Canadians are indeed ready for change. Turns out Peter MacKay is also ready for change," said Mulcair to hoots and hollers from the crowd.

CUPE members rally in downtown Toronto on March 21, 2015. CUPE has been a long-time supporter of the New Democrats. (CBC)

"A strong opponent, I really do wish him the best. But I think it's only fair to say that a lot of people seem to be leaving Stephen Harper's ship these days."

CUPE has been a long-time supporter of the New Democrats. Mulcair acknowledged this in his speech, saying the two have worked "arm and arm to reduce inequality." His speech was drowned out several times over chants of N-D-P.

Shortly after Mulcair's speech, CUPE 79, the Toronto branch of the union, voted to affiliate themselves with the New Democrats for the upcoming election. The local union represents more than 20,000 employees in Toronto.

NDP embroiled in controversy over satellite offices

Mulcair's party has also been dogged by controversy this week. The federal NDP has faced criticism over their now-closed satellite offices in Montreal, Quebec City and Toronto.

The House of Commons' board of internal economy has confirmed dozens of NDP MPs may soon find their expense claims being rejected by House administration as a result of their failure to repay $2.7 million that went to fund the offices.

Mulcair has said the NDP's rise in the polls is driving the controversy.

"It's just our Liberal and Conservative adversaries using their majority to try to frustrate the party that's coming up in the polls, and doing well compared to the two old-line parties," he said Wednesday.

Mulcair did not talk about the expense claims in Friday's speech.