REGINA - Saskatchewan is seeking intervener status in British Columbia's reference case over the flow of heavy oil through that province.

Attorney General Don Morgan says Saskatchewan is dismayed that the Trans Mountain pipeline expansion continues to be held up by unreasonable delays.

The case before the B.C. Court of Appeal asks whether amendments the B.C. government is proposing to the Environmental Management Act are valid.

The case also asks whether B.C. has the authority to control  shipment of heavy oils based on any impact spills could have on the environment, human health or communities.

B.C. is also asking the court whether the amendments would be overridden by federal law.

The $7.4-billion Kinder Morgan project would double an existing pipeline from Edmonton to Burnaby, B.C., in an effort to sell more fuel to Asian markets.