MONTREAL -- Progressives from across Canada need to unite with Quebecers to form the first "social-democratic" NDP government in the country's history, Tom Mulcair said Tuesday as he rebooted his campaign kickoff in Montreal.

Mulcair staged the event in front of Beaver Lake on top of Mount Royal park, the same location he chose in 2007 to announce he would run for the NDP, becoming only the second-ever New Democrat elected in the province.

Since then the party's fortunes have exploded in Quebec, sending 59 MPs to Ottawa out of 75 available seats.

But the party knows it needs people outside Quebec to vote NDP if it stands any chance of forming even a minority government after the Oct. 19 election.

"The 'orange wave' started here in Quebec and on Oct. 19 we can finish the job," Mulcair said, dismissing a scornful Stephen Harper rebuke from the day before.

"Since Stephen Harper came to power he's never faced a more tough, real and determined opposition than the NDP," Mulcair said.

"Remember the two previous (Liberal party) leaders? Harper passed over them like a steamroller."

Mulcair defended his party's pledge to increase the corporate tax rate, a policy platform Harper said would help wreck the economy.

An NDP government would institute a "slight and gradual increase" of the tax rate for large corporations, he said, in order "to have the capacity to do the things we want to do for the best interests of the public," such as a national child daycare program.

The NDP would also decrease the tax rate for small and medium-sized businesses from 11 per cent to nine per cent, since, he said, it's the smaller companies that create most of the jobs.

"We want the job creators to do just that -- create more jobs," he said.

Mulcair didn't just defend his party from Harper's attacks. He also launched a few of his own.

Harper is looking "weak and vulnerable" on the trade file, Mulcair said, as the government continues to negotiate a massive trade pact with Asian-Pacific nations during a lengthy election campaign.

"He was never a very good negotiator to begin with, but we are concerned about very important subjects," Mulcair said, such as whether the Tories will open Canada's market for eggs, milk, cheese and poultry to foreign competitors, something the NDP is against.

The Conservatives often accuse the NDP of being against trade deals, but Mulcair said it is crucial to examine the fine print.

"We are also enthusiastically in favour of a trade deal with our Pacific partners, but what is going to happen? What is going to be on the table with Mr. Harper negotiating that right in the middle of an election campaign?"

Mulcair also defended his party's close relationship with labour unions, another subject of Conservative attacks.

Harper said on Monday in Quebec the NDP is controlled by the unions.

Mulcair responded that he is proud of his party's ties to organized labour.

"Unions are responsible for the greatest reductions in social inequality over the past 200 years" he said. "We can be very proud of the things that we take for granted today like protection for workplace accidents and having a weekend."