Liberal Leader Justin Trudeau held an evening rally with Ontario Premier Kathleen Wynne in Toronto Monday, hours after brushing off questions about whether his close relationship with Wynne could hurt him.

Before introducing Trudeau as "the next prime minister" at Monday night's rally, Wynne lashed out at both Conservative Leader Stephen Harper and NDP Leader Tom Mulcair.

"We said we were going to implement the Ontario Retirement Pension plan and we're doing that despite Stephen Harper," Wynne said.

On Mulcair, Wynne said he "talks a good game" on child care, wage increases and Senate reform, but his plans are unclear.

"The ideas are either incomplete, or they're unworkable, or they're impossible," Wynne said, as the crowd booed at the mention of the Opposition leader's name.

We need a new government & a new kind of leadership in Ottawa. <a href="https://twitter.com/hashtag/cdnpoli?src=hash">#cdnpoli</a> <a href="https://twitter.com/hashtag/onpoli?src=hash">#onpoli</a> <a href="http://t.co/qaZ90kouP0">pic.twitter.com/qaZ90kouP0</a> —@Kathleen_Wynne

During a campaign stop in Ajax, east of Toronto, earlier in the day, Trudeau was asked whether the police investigations into the Ontario government or Wynne's decision to privatize the power company Hydro One could hurt the federal Liberals in the campaign.

Trudeau said he had made "co-operative, collaborative" leadership with premiers a priority in his campaign, and said as prime minister he would commit to working closely with "a number of them." He also defended Wynne's attempt to proceed with a provincial pension plan, saying it was Harper's failure to secure Canadians' pensions that made the move necessary.

Trudeau rejects Liberal-NDP coalition

During the Ajax campaign stop, Trudeau also promised to ease the government burden on middle-class paycheques, saying the middle class has been neglected by Harper's Conservatives for nearly a decade.

"The Conservatives believe the way to grow the economy is to make wealthy people wealthier, to give the most to the people who need it the least," Trudeau said.

"This is a tougher economy than it needs to be for the middle class and those who wish to join it. Mr. Harper doesn't see that from 24 Sussex (Drive)."​

Trudeau flatly ruled out a Liberal-NDP coalition to prevent Harper's Conservatives from forming another government if no party has a majority after the Oct. 19 vote.

"I do not believe in formal coalitions," Trudeau said Monday.

"The Liberal party is, of course, as it always has been, open to working with other parties elected in the House of Commons to pass the right legislation to help Canadians."

Campaigning on his plan to ease the government burden on middle-class paycheques , Trudeau dismissed the idea of governing in partnership with Mulcair, saying the New Democrat leader has no plans for the economy.

"I don't believe in backroom deals or arrangements amongst leaders," Trudeau said at a campaign stop in suburban Ajax, Ont.

"I believe that Canadians should have the full range of choices so that they can pick the team with the better plan."

Liberal Leader Justin Trudeau poses with a young Team Trudeau supporter during the campaign stop in Toronto on Monday. (Darren Calabrese/The Canadian Press)

Raising taxes on the wealthy

Trudeau said the NDP would also hike taxes on corporations, stalling economic growth, but would not have the courage to increase taxes on high income earners to help fund a tax cut for the middle class, said Trudeau.

A Liberal government would raise taxes on the richest Canadians while cutting taxes for those making between $44,000 and $89,000.

"You deserve a plan that offers real growth for the middle class, not just a different government, but a better one," he said.

"We will stop giving government cheques to wealthy families so we can give more to the middle class and lower-income families."

Trudeau also said his proposal for a new tax-free child benefit would put more money in the pockets of those who need it most.

He said Harper is giving money to the wealthy while neglecting the middle class and that has to change.

Wright-Duffy 'cover-up'

Trudeau also got in another dig at Harper over the Mike Duffy scandal, saying it's time for the prime minister to come clean about the involvement of a number of his staff members, some of whom are working on the Conservative leader's election campaign.

"Mr. Harper's decision not just to promote and protect people who seem to have been at the heart of this cover-up, and keep them actively engaged in his campaign, really illustrates that Mr. Harper doesn't have much respect for the office that he holds or for the intelligence of Canadians."