CALGARY -- The economic debate in Calgary will be one of the most critical moments of the campaign for Tom Mulcair and the NDP has released its fiscal breakdown in preparation for this political scrapping session.

Mulcair knows he is the main target as his party has been contending for top spot in a series of public opinion polls. His big test now is proving the NDP is the most credible alternative to the Conservatives.

"All the guns are going to be turned on us for the next few weeks and you know what, we're up to the challenge ... bring that fight on," Mulcair said at a rally in Calgary on Tuesday night.

The modern-day NDP has never been in the front runner position leading up to election day, which has put pressure on the party to explain how they would balance the books and roll out big ticket promises without dipping into deficit.

Mulcair tried to get out ahead of the other parties Wednesday as the NDP unveiled its balance sheet.

"I think they're happy to put that out and I think they want that out in advance of the debate so that people aren't saying 'your numbers don't add up'," said McMaster political science professor Peter Graefe.

"They can say 'well, here's our numbers.' And people can kind of quibble about specifics but they can say 'look, we have a plan'," Graefe said.

Part of that plan includes a pledge to balance the books and run an annual surplus.

The party projects the surplus will be $4.1 billion in 2016-2017, $3.4 billion in 2017-2018, $3 billion in 2018-2019 and $4 billion in 2019-2020.

"When it comes to our fiscal plan, we will not hit the snooze button as Stephen Harper has on the economy," said Ontario NDP candidate Andrew Thomson, a former Saskatchewan finance minister who is running against Finance Minister Joe Oliver.

"We will not hit the panic button like Justin Trudeau has on spending. We will take a prudent and responsible approach to balancing the budget."

The NDP also laid out other fiscal plans, such as a promise to boost the corporate income tax rate from 15 per cent to 17 per cent. The party says the tax hike will mean $3.7 billion in extra annual revenues.

It also plans to make changes such as ending fossil fuel subsidies to raise $240 million annually and close stock option loopholes for CEOs and senior executives to accumulate $500 million a year.

Mulcair said the NDP's path to form government involves being "very clear" about its proposals.

"Before the election, we are going to tell Canadians what we are going to do," Mulcair said.

"Once we are elected, we are actually going to do it; it has never been tried."

NDP strategist Robin Sears, who once served as the party's national director, said Mulcair now needs to zero in on Stephen Harper in the debate.

"I think that I would encourage him to invest his energy and passion in whacking Stephen Harper over the head rather than squabbling with Justin," he said.

"The ballot question in this campaign is who is the best Harper killer."