As House GOP leaders ready a high-profile tax bill that would force quick approval of the Keystone XL pipeline, five of Senate Majority Leader Harry Reid's (D-Nev.) caucus members yesterday warned him that they would "strongly oppose" any language fast-tracking the Canada-to-U.S. project.

Sen. Bernie Sanders (I-Vt.), who last month spearheaded a push to secure an inspector general review of the State Department's decisionmaking process on Keystone XL, joined Sens. Sheldon Whitehouse (D-R.I.), Patrick Leahy (D-Vt.), Ron Wyden (D-Ore.) and Frank Lautenberg (D-N.J.) in the pipeline letter to Reid. "It is necessary and appropriate to wait for the results" of that State IG review before advancing any legislative effort on the 1,700-mile XL link, they wrote.

The five senators blasted the GOP bid to speed construction of the pipeline, which would significantly boost U.S. imports of emissions-intensive Canadian oil sands crude, as a "rubber stamp" that "would also set a troubling precedent by removing the State Department from its responsibility for review of pipelines crossing international borders."

The Senate push against House Republicans' pipeline provision comes as Canadian Prime Minister Stephen Harper arrives in Washington to meet with President Obama today on security and trade. While the $7 billion oil sands crude link trumpeted by Harper's government is not on the official agenda, green activists plan to greet him with an anti-pipeline protest in front of the Canadian embassy.

The House Republicans' Keystone XL bill would set a 30-day timeframe for Obama administration approval of the pipeline and shift authority over a final permit decision to the independent Federal Energy Regulatory Commission rather than the State Department, plagued by conflict-of-interest charges that helped drive calls for the IG review from Sanders and many environmental groups.

A similar Senate GOP bill would preserve State's authority over the project and set a 60-day clock for sign-off on the pipeline (E&E Daily, Nov. 30). Both Republican proposals would integrate the results of a rerouting compromise in the state of Nebraska into a final review and green light for Keystone XL.

The Senate GOP measure had one Democratic co-sponsor, West Virginia Sen. Joe Manchin, as of Monday.

House Republicans are not planning a vote this week on the tax bill that is poised to include Keystone XL provisions, as well as an extension of White House-backed payroll tax cuts and a rider blocking U.S. EPA rules for industrial boiler emissions. A GOP leadership aide, however, said earlier this week that party leaders are working on a broad payroll tax measure that will likely include a federal pay freeze to pay for the extension.

Click here to read the senators' letter to Reid.

Reporter Emily Yehle contributed.