Massachusetts' two U.S. senators are planning to vote against the Keystone XL pipeline project.

Sens. Elizabeth Warren and Edward Markey say they're opposed to the crude-oil pipeline, which would run from Canadian tar sands to Gulf coast refineries.

Markey has been the most vocal.

He said he agrees with President Barack Obama, who recently said the project won't bring down gas prices in the United States, but will instead allow Canada to ship oil to the Gulf coast where it will be sold elsewhere.

Markey said he's tried to counter that by offering amendments that would require the oil transported through the pipeline to stay in the United States.

Markey called the pipeline a way for oil companies to use America as a middleman for the energy interests of other countries.