Energy companies have been trying to get the Federal Energy Regulatory Commission to slow down the construction of a controversial pipeline to carry gas from the Midwest to Gulf Coast refineries.

The president-elect and some Democrats in Congress have criticized the pipeline for having a high rate of leaks, and the commission has been asked to consider a wide range of options to reduce the risk of such leaks.

Trump has been accused of having ties to companies that work on the project, and some Republicans in Congress and Trump have threatened to block the project if he’s elected.

If the commission approves the project this fall, it will be one of the largest in U.S. history, carrying more than 1.6 billion cubic feet of natural gas a day to Southern California and its environs.