More than a dozen Democrats on Wednesday called on the State Department’s Office of Inspector General to conduct a probe into how the agency has handled the permitting process for a proposed massive oil pipeline between the United States and Canada.

Three senators and 11 House members — led by Sen. Bernard Sanders (I-Vt.) and Rep. Steve Cohen (D-Tenn.) — wrote Deputy Inspector General Harold W. Geisel asking for scrutiny of how the State Department reviewed TransCanada’s permit application for its Keystone XL extension.

Opponents of the project have criticized the process for several reasons, including that the private contractor State hired to help conduct the review did not disclose that it had previously worked on a TransCanada project.

Juliet Eilperin