The Conservatives are promising to maintain budgetary surpluses over the next four years even as spending for their campaign promises ramps up.

Conservative Leader Stephen Harper outlined his party's platform during a rally in Surrey, B.C., today, where the Tories have made several costly campaign promises in an effort to woo voters in the region. The presentation also included three pre-taped videos featuring Tory supporters from various parts of the country.

The platform document projects a surplus of $1.6 billion next year. That surplus drops to $1.4 billion in 2017/18, then falls further,to $947 million in 2018/19, as some promises from this campaign finally kick in in those two years.

Most notably, that's when the Conservatives expect the Trans-Pacific Partnership trade agreement will be ratified, and farmers will begin to use the $4.3-billion compensation fund, for example.

Most of the party's campaign promises have been released already but there are a few surprises in today's 159-page document.

The Tories are promising to extend a program that has prison inmates help build homes for Habitat for Humanity, which is expected to cost $3 million.

There is also an expansion of a program that helps students in the skilled trades find summer jobs that will amount to $10 million over four years.

A Conservative party strategist highlighted what he describes as a key difference between his party's platform and the spending commitments from the NDP and the Liberals.

In the fourth year of a Conservative mandate, new spending on promises from this campaign would total $2.9 billion. In that same year, the strategist says, the NDP would spend about $11 billion on campaign promises, while the Liberals are promising to spend just under $37 billion, according to the strategist.

By that fourth year, the Conservatives are expecting a budgetary surplus of $2.4 billion under their plan.

"The Liberals and NDP made tens of billions in promises with money they do not have," Harper told the audience.

"Despite what the NDP and Liberals says, we cannot borrow or tax our way to prosperity."

Budget freeze continues

The Conservatives are also promising contingency funds each year that are not included in the surplus projections. It starts at $1 billion next year and it grows to $3 billion in the fourth year.

The party is also promising to continue a departmental budget freeze for another year, which it predicts will bring in about $500 million in revenue.

The Conservatives are the last of the three major parties to release a full platform of promises. The NDP is having its own platform release event this morning, and the Liberals released their document on Monday. The Conservative plan is coming this late in part because the party was waiting for the Trans-Pacific Partnership trade negotiations to conclude.

Representatives from Canada and 11 other countries reached the deal to create the largest-ever regional trading bloc four days ago in Atlanta, and the party's platform includes measures to support industries affected by the deal, including the supports for farmers and a $1-billion package for the auto industry.