A prominent conservative group offered to sell its endorsement to FedEx for more than $2 million to help the package delivery company win a contentious legislative dispute, according to Politico.com.

But when FedEx refused to pay the American Conservative Union, the group sided with UPS, FedEx's rival in the dispute.

FedEx and UPS are battling over a provision being weighed by Congress that would expand union power at FedEx.

The House passed a bill that would force FedEx, which currently has one U.S. union contract for its entire express business, to negotiate union contracts for individual locations -- like UPS -- which FedEx argues would make it much more difficult to promise worldwide regularity for deliveries. The bill is awaiting action in the Senate.

In a three-page private letter to FedEx dated June 30 and obtained by Politico.com, ACU offered a range of services for the more than $2 million, including "Producing op-eds and articles written by ACU's Chairman David Keene and/or other members of ACU's board of directors."

After FedEx said it rejected the offer, Keene reportedly signed onto a two-page July 15 letter supporting UPS as part of a conservative consortium that accused FedEx of "misleading the public and legislators."

"Clearly the ACU shopped their beliefs and UPS bought," Maury Lane, FedEx's director of corporate communications told Politico.com.

But Dennis Whitfield, ACU's executive vice president, said that neither the group nor Keene took any money from UPS and that the group has never received a response to its initial offer to FedEx. He said Keene endorsed the second letter as an individual, even though the letter contained the logo of ACU.

Click here to read the Politico story.