The Senate passed its own version of patent reform legislation earlier in the year that included Coburn's amendment which, in effect, would prohibit the federal government from using patent fees for non-patent related spending.

The House did not take the bill up, in part because of opposition to that amendment, and instead added language to the America Invents Act (H.R.1249) that creates a reserve fund for unused patent fees. Leahy and other proponents of the bill say this amounts to the same intended effect of the Coburn amendment.

In his speech on the Senate floor late Wednesday afternoon, Leahy pointed out that the House had already rejected the Coburn language, and sending it back would likely spell the end of patent reform efforts this year.

"We shouldn't kill this bill with this amendment," said Leahy. "Instead, we should reject the amendment and pass the bill."

Coburn has yet to come to the floor to present that amendment or defend its contents.

The underlying legislation of the bill would change the U.S. from a first-to-invent to a first-inventor-to-file patent system, a move proponents say would bring the U.S. patent system closer to systems already used by most of the rest of the world.