– The U.S. Senate could reauthorize the Export-Import Bank with some reforms Sunday as an amendment to a transportation bill.

The 81-year-old government-run bank, which insures loans and offers other financial services to facilitate the sale of U.S. products to foreign markets, has been the subject of a major political showdown.

The U.S. Chamber of Commerce and the AFL-CIO want to keep it going, as does the Obama administration. But some conservative Republicans, who call it “crony capitalism,” and a few major corporations that feel it gives competitors an unfair advantage want it killed.

The bank’s reauthorization lapsed in June as a result of congressional inaction.

Now, Ex-Im, as the bank is known, seems likely to be resurrected by the Senate as an addendum to must-pass transportation legislation.

A procedural vote on an earlier Ex-Im amendment to the defense bill garnered 65 votes before the amendment was withdrawn in a deal between the bank’s supporters and the Senate’s Republican leadership.

This time, the amendment is set to stay.

Sens. Amy Klobuchar and Al Franken of Minnesota, both Democrats, support reauthorization of the bank. Both senators have said the bank helps small businesses strike deals with foreign buyers that they would not otherwise be able to make.

Klobuchar and Franken both point out that other countries, especially China, offer similar services that will draw sales away from U.S. businesses if the bank dies.

Still, the expected reauthorization of Ex-Im as a rider to the highway bill drew an angry rebuke from the conservative Heritage Foundation’s Heritage Action political action committee. The PAC and Tea Party stalwarts have threatened to target Republicans who vote for reauthorization. Those threats led the House not to take up Ex-Im reauthorization.

Dan Holler, Heritage Action’s spokesman, sent an e-mail Friday under the subject line “McConnell lied to reporters too.”

Holler claimed Senate Majority Leader Mitch McConnell’s spokespeople told journalists that the majority leader did not promise a second vote on Ex-Im.

In fact, McConnell could allow second and third votes Sunday.

The first Sunday vote will be to invoke cloture to an amendment that ties reauthorization of the Export-Import Bank to repealing the national health care reform law. If that fails to get 60 votes, the Senate will then vote to invoke cloture on a stand-alone Ex-Im amendment that includes reforms to the bank offered by Sen. Mark Kirk, R-Ill.