REGINA -- The federal New Democrats and leader Tom Mulcair are running up against a wall in Saskatchewan.

Premier Brad Wall entered the federal election fray Tuesday by saying that voters should consider other choices when casting their ballots.

"If they're looking at options in the federal election, the NDP's interests, the NDP's policies in this federal election, do not align with the interests of the people in the province of Saskatchewan," said Wall.

The premier, who leads the small-c conservative Saskatchewan Party, specifically pointed to the NDP's opposition to the Trans-Pacific Partnership.

The agreement between Canada and 11 other Pacific Rim countries has been billed as the largest trade deal in history. It could have implications for hundreds of millions of people, hundreds of products and industries, and for long-term relationships between countries on four continents.

"The Trans-Pacific Partnership, that free-trade agreement, I think is the most important federal issue in this election campaign," said Wall.

"While you're going to have give and take with any trade agreement, this one is decidedly good for Saskatchewan."

The deal would mean an end to tariffs on canola seed or oil, pork, beef and agricultural equipment exports, Wall said.

Wall sent letters to Mulcair, Conservative Leader Stephen Harper and Liberal Leader Justin Trudeau asking for their positions on genetically modified crops, pipelines and equalization.

The equalization program sees more than $17 billion a year transferred to poorer provinces to fund public services.

Wall has expressed frustration with the formula. He says provinces such as Manitoba and Quebec are entitled to higher equalization payments because the formula doesn't take into account the wealth hydro generates for them. The formula does take into account non-renewable resource revenue from oil and gas.

During the 2006 federal election, the Conservatives promised to remove non-renewable resource revenues from the equalization formula. That hasn't happened.

Wall said the position of all three leaders on the issue "is disappointing."

"They all say the same thing, unfortunately, which is basically kind of a punt back to the provinces.

"I can kind of understand that, except the challenge there is that if we don't have federal leadership on equalization, we're never going to see reform. It won't come at the provincial level because the views are so disparate, the interests are so different at the provincial table. There's going to need to be federal leadership if we're ever going to have a modernized, more fair equalization formula."