EDMONTON -- Alberta is putting an expiry date on proposed legislation that would allow the province to regulate oil and gas shipments.

The government has said it might use such a law against British Columbia if that province continues to block an expansion of the Trans Mountain pipeline.

Parties on both sides of the house voted on Wednesday to accept an Alberta Party amendment to put a two-year limit on the bill.

It proposes that Alberta have the power to restrict and redirect flows of oil, gasoline and natural gas to maximize profits, given the bottlenecks in pipelines.

The amendment gives the government the option to extend the bill after the two-year limit, but it would need to go back to the legislature for approval.

Energy Minister Marg McCuaig-Boyd told the house that two years is a reasonable time and the amendment doesn't tie the government's hands.

Premier Rachel Notley has threatened consequences to B.C. for opposing and delaying Kinder Morgan's Trans Mountain project.

The bill has the potential to cause gasoline and other fuel-related prices to spike in B.C.

The dispute is heading for a showdown on May 31. That's the date Kinder Morgan Canada has set for a decision on whether it might cancel the $7.4-billion project.