In a speech that touched on government corruption, the struggling middle class and income inequality, NDP Leader Thomas Mulcair painted his party as the "better option" for voters seeking an alternative in Ottawa.

Addressing his caucus in Saskatoon Wednesday morning, Mulcair maintained the NDP was the only party that "speaks on behalf of all Canadians."

The NDP leader took snipes at both the Conservatives and the Liberals, insisting both parties were cut from the same cloth.

He said Canadians have suffered under years of Liberal and Conservative leadership, with widening income disparity, the loss of well-paying manufacturing jobs and declining wages.

He added that the Senate expenses scandal -- which has seen the RCMP launch investigations into four senators, including Senators Mike Duffy, Patrick Brazeau and Pamela Wallin, as well as Mac Harb, who has since resigned -- is just another example of the "lack of accountability" and the "culture of entitlement" that has dominated federal politics.

The NDP has made the abolition of the Senate a main part of its platform.

"Canadians have had enough," he said. "The fact of the matter is Ottawa is broken and while the Liberals simply wait for their turn at the trough, the NDP is still the only party that can and will fix it."

Mulcair also addressed the high youth unemployment rate and attacked Conservative restrictions on employment insurance benefits.

The speech came amid recent polling numbers showing rising support for the Liberals under the leadership of Justin Trudeau.

While the party is maintaining that its main goal going into the fall session is taking the Conservative government to task, CTV's Mercedes Stephenson reports that, behind closed doors, they're also discussing how to deal with the Liberals.

She added that the party has been showing its caucus members polling numbers for past Liberal leaders Stephane Dion and Michael Ignatieff to put Trudeau's popularity into context.

An internal party strategy note obtained by CTV's Richard Madan on Tuesday compares how the NDP is faring against Trudeau versus Dion and Ignatieff.

The historical survey data, taken from three polling firms, shows that at the height of Dion’s popularity and that of the NDP, Dion led by 30 percentage points.

With Ignatieff, the NDP trailed the Liberals by 22 percentage points. But against Trudeau, the difference is 11.

The NDP’s caucus meeting wraps up Wednesday.