VANCOUVER -- British Columbia's attorney general says the NDP government will not artificially delay permits for the Trans Mountain pipeline, despite the premier's vow to use every available tool to stop the project.

David Eby said he's been tasked by Premier John Horgan to identify options to halt Kinder Morgan Canada's $7.4-billion expansion of its Alberta-to-B.C. pipeline, which has already been approved by Ottawa and the previous B.C. government.

Eby said the province cannot deliberately stall on permits without risking a very costly lawsuit, but it can ensure that permits require that construction be done in a way that minimizes spills, protects the environment and ensures appropriate cleanup.

"I've been tasked by the premier to identify our options. There is an important piece to that, which is that we must do so within the laws of British Columbia and Canada, because if we don't, we'll be sued," Eby told Kamloops radio station CHNL.

"We'll end up paying hundreds of millions of dollars that should be going to schools and hospitals to an oil company and that is not a goal that anybody's looking for."

Trans Mountain, a subsidiary of Kinder Morgan Canada, declined comment on Eby's remarks but said it's in an ongoing process of seeking and receiving permits from the necessary agencies, as construction of the project is phased.

Eby did not immediately respond to requests for comment from The Canadian Press.

Horgan's NDP won 41 seats in the province's May 9 election, shy of the 44 needed to mount a majority. But the Greens, who hold three seats, signed an agreement to support the New Democrats in a minority government.

The agreement states the government will "immediately employ every tool available to stop" the pipeline expansion.

A mandate letter issued by Horgan to Environment Minister George Heyman on Monday softens the language slightly, saying instead that he must employ every tool available to "defend B.C.'s interests in the face of" the expansion.

James Coleman, an energy law professor at Southern Methodist University who previously worked at the University of Calgary, said Eby's remarks reflect the government's need to be cautious about what it says and does.

"That's certainly what you'd want to say. If you want to avoid compensation (to Trans Mountain), you wouldn't want to give the suggestion that you were deliberately delaying or acting in bad faith," he said.

"That's one of those challenges the government faces. Because it has been so explicit that it's going to use every tool to try and block this pipeline, that they may worry that the courts will see the government's actions as being in bad faith."

First Nations and environmental groups have filed lawsuits against the federal government's approval of the project. Some groups have also launched legal challenges of B.C.'s environmental certificate.

The NDP government has not said what it plans to do about the lawsuits, but Coleman said if it is looking to avoid compensation, then the normal move would be to defend the certificate.

"The question is: Is that a half-hearted defence?" he asked. "I think that remains to be seen."

Horgan said at a joint news conference with Prime Minister Justin Trudeau in Ottawa on Tuesday that he hasn't yet been briefed by his attorney general but he has spoken with First Nations who have filed lawsuits against the federal government.

"I've met with the leadership of the Tsleil-Waututh, Musqueam and Squamish First Nations and have heard very clearly their views on the matter, and we'll deal with those in the days and weeks ahead," he said.

Charlene Aleck, an elected councillor of the Tsleil-Waututh, said she had met with Horgan and felt confident he supports their efforts to halt the pipeline expansion. However, Horgan has not signalled that he intends to join their legal fight, she said.

Green party Leader Andrew Weaver said in a statement that he understands Eby's points and expects they are not indicative of a broader change in the NDP's stance on the pipeline.

"As an opposition party, we will remain steadfast in calling on the NDP government to use every legally available tool to stop the pipeline from going ahead," Weaver said.