The Export-Import Bank was last reauthorized in September 2014. That authorization expired last night, June 30, at midnight. This puts Ex-Im in a unique position — it is funded through the end of the fiscal year (Sept. 30, 2015); it has more than $100 billion in loans and guarantees outstanding; no legislation has passed terminating it.

So there's little precedent as to how Ex-Im should continue to exist. Ex-Im on Twitter today referred to a "lapse in our authorization," but that's not precise. Under the law, as I explained in a blog post this week, Ex-Im is now in liquidation.

President Obama wants to take Ex-Im out of liquidation and get it back to work subsidizing foreign companies and governments that buy Boeing jets and other U.S. goods.

One worry among conservatives who have opposed Ex-Im is that Ex-Im is still operating as if it is simply on a time-out — that is, is the agency liquidating and winding down as the law requires, or is it just taking a break from finalizing new deals?

For that reason, Sen. Marco Rubio, a presidential candidate and a leading opponent of Ex-Im, has written a letter to Ex-Im Chairman Fred Hochberg, demanding details of its liquidation plan. Rubio's office tells me that conservative Sens. Mike Lee, Ted Cruz, Rand Paul, Ben Sasse, and Pat Toomey have also signed on to the letter.

The letter, which will be released publicly this afternoon, requests:

clarity on your plan for an orderly liquidation, including:

• A timeline for completion of orderly liquidation;

• A report on which employees are participating in the orderly liquidation and why certain employees' employment is necessary during an orderly liquidation;

• The return to the General Services Administration (GSA) of the Ex-Im Bank's properties;

• The end of the administration of www.exim.gov;

• The continuance of servicing existing Ex-Im loans, obligations that have not completely matured, direct loans, or loan guarantees acquired or issued entered before sunset date; and

• Estimated savings on federal funding through September 30, 2015, through the orderly liquidation and wind-down of the Ex-Im Bank's operations.

Moreover, the Comptroller General said that "payment of obligations incurred prior to the termination date is usually made by a successor agency, or by another agency pursuant to an Economy Act, 31 U.S.C. Sec. 1535, agreement entered into prior to the termination date." We respectfully request which agency will be deemed your successor agency and, additionally, would like the estimated payments of obligations incurred.

"Under federal law," Rubio says in a statement, "the agency cannot continue to participate in the crony behavior that brought deserved-scrutiny from the American people. The American taxpayer is finished financing the Export-Import Bank's corporate welfare operation. The agency must terminate and the 'orderly liquidation' must begin immediately."