Sen. John Ensign (R-Nev.) said Wednesday that the fight over the housing bill could extend through the weekend if Democrats don't give him a vote on an amendment to extend several tax breaks promoting renewable energy.

Ensign said he told the senior senator from his state, Majority Leader Harry Reid (D), as well as bill sponsors Sens. Chris Dodd (D-Conn.) and Richard Shelby (R-Ala.), that he was prepared "to go to the wall on this one."

Democrats say they only want to allow amendments that are germane to the pending housing bill, which would institute a whopping $300 billion expansion for the Federal Housing Administration's insurance program for struggling borrowers. They're concerned that adding the Ensign-Cantwell amendment, as well as another plan offered by Sen. Bernie Sanders (I-Vt.) to expand home-heating assistance for low-income residents, could complicate efforts to reconcile the measure with the House. A housing bill that passed the House the last month does not include the renewable-energy package.

"Our responsibility is to act as the Senate, as far as I'm concerned," Ensign said.

His threat complicates an effort by Reid to finish the housing bill and give final passage to an emergency wartime supplemental spending bill and an electronic surveillance bill before Congress leaves for its Fourth of July recess at week's end.

The housing bill has overwhelming support and cleared a key hurdle Tuesday when the Senate voted to limit debate, 83-9. But without a unanimous-consent agreement, the Senate may be forced into several other time-consuming procedural votes that could stall final action.

Reid said Tuesday night that it would be a "shame " if the bill could not pass before the recess and pleaded with senators not to "dig in their heels."

Dodd fumed on the floor Wednesday morning that the fight would delay aid to thousands of struggling homeowners.

"One United States senator has said 'No, my bill is more important,'" Dodd said.