More than 450 business leaders are speaking out against the Trans Mountain expansion project.

Notably, OpenText Co-Founder Tim Bray is among the long list of signatories of an open letter urging British Columbia Premier John Horgan to stand strong in his ongoing fight to block the project.

"Saying 'no' to the Trans Mountain pipeline not only protects the hundreds of thousands of jobs in British Columbia that depend on a clean, protected environment, saying 'no' is a crucial signal to companies, industries and investors that we want to build the future in areas like clean energy and technology," Tim Bray said in a release. "Saying 'no' to Kinder Morgan is saying 'yes' to British Columbia's real future."

In the letter, the leaders argue industries including tech, tourism and construction create more jobs that the oil, gas, and mining sectors combined.

They also argue the project is “out of step with the future prosperity of Canada” and “out of sync” with Indigenous peoples’ wishes.

Kinder Morgan has set a May 31 deadline to get the clarity it needs for its shareholders in order to go through with the project amid mounting political uncertainty in the westernmost provinces. Horgan has maintained his opposition to the project as B.C. plans to take its case to the B.C. Court of Appeal by April 30.