The B.C. government announced Wednesday it will file a reference case it has been preparing regarding the Kinder Morgan Trans Mountain Pipeline expansion.

The case will clarify whether the province has the right to restrict diluted bitumen shipments to its coast on environmental grounds. It's seeking an answer to a constitutional question that could have wide-ranging impacts.

B.C.'s Attorney General David Eby said in a news release that the government's lawyers will file the case in the B.C. Court of Appeal by April 30, 2018.

"The B.C. Court of Appeal is the highest court to which the province can refer questions of this nature under B.C.'s Constitutional Question Act," Eby said the release.

The exact wording of the question hasn't been confirmed, so officials will have to determine how they want it phrased.

Before April 30, the reference case will first need to be approved by cabinet. Notice must be given to the federal government once it is filed in the court registry. The court will then schedule a hearing.

The impending court challenge appears to have made Kinder Morgan, a Texas-based energy infrastructure company, anxious about the future of its pipeline expansion. Earlier this month, it pushed the brakes on construction and halted all non-essential spending until it can be assured the project will be able to move forward.

The company set a deadline of May 31 to decide whether to go through with the pipeline expansion.

It's unclear if B.C.'s reference case will be decided before that deadline.

“Everybody understands the interests,” Eby told the Canadian Press. “Certainly, we have an interest in B.C. about having an answer to this as soon as possible. Everybody wants clarity around this so we'll be moving and we are moving as quickly as we can.”

Joel Bakan, a professor at UBC's law school, told CTV News Tuesday that although the pipeline is a federal undertaking, the Supreme Court of Canada has said there's still space for robust provincial regulations "So long as it doesn't impair the operations of the pipeline."

The project has caused friction between B.C., Alberta and the federal government in recent weeks. On Sunday, Prime Minister Justin Trudeau summoned the premiers of both provinces to Ottawa to talk about the future of the pipeline.

After the meeting, the three remained at an impasse with Alberta Premier Rachel Notley and Trudeau saying the pipeline will be built, and B.C. Premier John Horgan stating he will continue to fight to protect B.C.'s coast.

On Wednesday, the Angus Reid Institute also released a poll suggesting most British Columbians' top concern about the pipeline expansion involves a spill or accident involving a tanker.

The pipeline tension appears to have followed Trudeau halfway around the world to London, England where he was greeted by pipeline protesters Wednesday at the Canadian High Commission.

With files from The Canadian Press