PORTLAND, Maine — Several Maine environmental groups are speaking out against a pipeline that would carry Canadian oil across the continental United States.

The Natural Resources Council of Maine, Sierra Club Maine, Natural Resources Defense Council and National Wildlife Federation are holding public events Thursday to speak out against the tar sands oil pipeline and a proposed project to pump tar sands oil from Canada to Portland Harbor.

The groups are also urging Maine’s congressional delegation to oppose legislation to approve the Keystone XL tar sands pipeline without completing the environmental review process.

President Barack Obama has rejected the pipeline, which would have taken oil from Alberta to the Texas Gulf Coast.