Top Democrats poised for powerful roles next year are demanding that major banks and ports preserve any records they have tied to potential imports or other deals involving Russian diesel.

Why it matters: Probing President Trump’s agreement with Moscow will be a priority if Democrats regain control of either or both chambers of Congress.

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• The new demand shows that inquiries will extend beyond the White House and into C-suites.

Driving the news: “[A]ny importation of Russian diesel into the U.S. raises significant legal questions and may be subject to legal action, as well as congressional investigations,” a new letter obtained by Axios states.

• It’s signed by Sens. Chris Coons (D-Del.), Elizabeth Warren (D-Mass.), Ron Wyden (D-Ore.), and Sheldon Whitehouse (D-R.I.).
• They’re in line to lead the powerful Foreign Relations, Banking, Finance and Judiciary Committees, respectively, if Democrats regain the Senate.

Rep. Greg Meeks (D-N.Y.), who’s in line for the Foreign Affairs Committee gavel if House control changes, also signed.

• It’s led by Sen. Jeanne Shaheen (D-N.H.), the top Foreign Relations Democrat who is not seeking reelection. Sen. Thom Tillis (R-N.C.), who is also retiring, signed as well.

State of play: The Wall Street recipients of Saturday’s letter are J.P. Morgan, Bank of America, Citi, Wells Fargo, Goldman Sachs and Morgan Stanley.

• The same letter went to port authorities for the ports of Houston, Beaumont, and Corpus Christi, Texas, and New York/New Jersey.

Catch up quick: Earlier this month Trump claimed an agreement to bring escalating Russian exports to global and U.S. markets, and the Treasury Department waived sanctions to help enable it.

Friction point: The lawmakers and other critics say it runs afoul of a bipartisan 2022 law barring imports of Russian oil, gas, and petroleum products.

• “The potential arrangement to import Russian diesel also raises significant national security concerns, given that it would finance Russia’s brutal and illegal war against Ukraine,” the letter states.

Yes, but: The Treasury Department has repeatedly claimed the agreement is legal.

The big picture: The new letter urges the banks and ports not to enable “purchase, transportation, importation, unloading, storage, financing, or distribution” of Russian diesel in the U.S.

• It also goes further, urging the parties not to facilitate any transactions for Russian diesel to other markets under the recent sanctions waiver.

Zoom in: Citing “anticipation of further congressional oversight,” it calls on recipients to preserve a wide range of potential records and communications related to “proposed or actual” transactions.

• Think contracts, shipping documents, vessel records and plenty more.
• The demand extends to any communications with suppliers, intermediaries and U.S. government officials.
• The lawmakers want confirmation by Wednesday that records are being preserved, plus details of any potential or actual Russian diesel transition.

What we’re watching: It’s unclear how much Russian diesel, if any, will reach U.S. shores.

• Reports Friday in S&P Global, Reuters and elsewhere identify a tanker that initially signaled a New York destination, while the shipping intelligence firm TankerTrackers on Friday said three tankers had signaled U.S. destinations.
• But ships’ planned destinations frequently change for one reason or another.

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