The Alberta government is going on the offensive to defend newly approved pipelines, vowing to intervene to stop any legal action aimed at slowing down the expansion of the Trans Mountain pipeline, a promise that sets the province's New Democrats on a collision course with their political cousins in B.C.

The government revealed its aggressive pipeline strategy during a Throne Speech on Thursday when Premier Rachel Notley's NDP set out its vision for Alberta as the provincial economy moves out of recession. The speech focused primarily on cutting school fees and the pipeline push at the centre of Ms. Notley's economic strategy, including a renewed effort to speed the approval of the Energy East pipeline linking the oil sands with Atlantic ports.

However, as Alberta's economy bounces back from the crash in oil prices, with some forecasts that it could lead the country in growth this year, there was little indication of how Ms. Notley's government will deal with a deficit expected to top $10-billion this year or a ballooning debt.

Story continues below advertisement

"Creating jobs, diversifying our economy, building pipelines and making life more affordable for families, that's your government's focus," Ms. Notley said in a statement.

At the centre of the Throne Speech, read by Lieutenant Governor Lois Mitchell, was a rare blanket promise to defend the $6.8-billion Trans Mountain pipeline expansion against any legal action. The project by Houston-based Kinder Morgan Inc. would almost triple the capacity of an existing pipeline running from Edmonton to Burnaby, B.C.

The federal government signed off in late 2016 after the pipeline was given the go-ahead by the National Energy Board, provided 157 conditions were met. B.C. Premier Christy Clark approved the project in early January, but it remains a source of fierce debate in the Pacific province as voters prepare to head to the polls in May.

Prime Minister Justin Trudeau defended his government's approval of the pipeline while touring the Vancouver Island town of Esquimalt on Thursday.

He said the approval represented a balance between the needs of the economy and the environment. "I just came from Alberta yesterday and people were frustrated with aspects of the leadership we've shown on climate change. Here in B.C. there are people frustrated with the leadership we've shown on moving forward on pipelines but I've said time and time again I understand this isn't something we can get unanimity on. We're going to both approve pipelines that are done responsibly and we're going to protect our coasts and oceans."

After the Throne Speech, Ms. Notley said her government didn't want any changes to the pipeline's priorities or prospects as a result of judicial reviews.

"We know that Kinder Morgan is fundamentally important to Albertans, to job creation and to promoting the growth of our economy. In every way that we can have agency we want to do that," she said. "We have an interest in preserving the process."

Story continues below advertisement

The Canadian Association of Petroleum Producers applauded the province's vow to defend the project. "We appreciate the relentless support of the Alberta government to diversify our markets, allowing our product to reach new customers," spokeswoman Chelsie Klassen said.

B.C NDP Leader John Horgan doesn't share Ms. Notley's enthusiasm for the project and has pledged to "use every tool" to scuttle the pipeline expansion. He's been joined by a number of environmental groups, mayors and aboriginal leaders who have prepared legal action to block the pipeline in provincial and federal jurisdictions.

Vancouver announced a court challenge in late February to quash the project.

There have been concerns raised about the environmental toll of an oil spill in Vancouver's harbour and the impact increased tanker traffic could have on local whale populations.

A senior critic for the B.C. NDP said the party is sticking to its opposition to the pipeline as the New Democrats seek a return to power for the first time since 2001. "They will act on what they believe to be the best interests of the citizens of Alberta. We will act on what we see as the best interests of the citizens of British Columbia," said Bruce Ralston, the MLA for Surrey-Whalley.

Ms. Notley and Mr. Horgan met in December to discuss the proposed pipeline expansion. Following their discussion, Ms. Notley said that she did not change Mr. Horgan's mind and the pair agreed to disagree.

Story continues below advertisement

Mr. Ralston said it would be "hypothetical" at this point to talk about options a B.C. NDP government could use to head off the expansion of the pipeline.

Derek Corrigan, the mayor of Burnaby, B.C., where bitumen would be loaded onto tankers for shipment, said in an interview on Thursday that he was not surprised by the tone taken in Alberta.

"I don't think they have shown any sign that they care one whit about what was going to happen to Burnaby." He added that Alberta's focus on its own interests is a "fatal flaw" in their plan.

With files from Justine Hunter in Victoria.