OTTAWA - The Federal Court of Appeal says it will reveal Wednesday whether a new set of legal challenges to the Trans Mountain pipeline project can proceed.

The federal government has twice approved a plan to twin an existing pipeline from Alberta's oilpatch to the B.C. coast.

Last year the Federal Court of Appeal tore up the original approval citing both an insufficient environment review and inadequate consultations with Indigenous communities.

The Liberals say they fixed both problems and approved the expansion a second time in June.

Environment groups still say there are not adequate protections for endangered marine species that will be affected by tanker traffic picking up oil from a terminal in suburban Vancouver.

Several First Nations say the federal government came into the most recent discussions having predetermined the outcome.