Prospects dimmed Monday for enactment of a $25 billion bailout for the faltering auto industry before year’s end, as congressional Democrats and the Bush administration seemed headed for a stalemate. Help for Detroit’s Big Three, which have been battered by the economic meltdown that has choked their sales and frozen their credit, is falling victim to a partisan fight over where the money should come from.

Senate Democrats said they would press ahead with their plan to carve out a portion of the $700 billion Wall Street bailout to pay for the loans, but aides in both parties and lobbyists tracking the plan acknowledged they did not currently have the votes to do so. The White House and congressional Republicans insist that the automaker bailout money instead come from redirecting a separate $25 billion loan program approved by Congress to help the industry develop more fuel-efficient vehicles.

In addition, besides opposing the use of any of the $700 billion for the automakers, the administration has told top lawmakers it does not plan to ask for the second half of that huge fund that Congress approved this fall to aid the financial industry, congressional officials said Monday.

The Treasury Department said its message on not tapping half the fund applied only to the next few days and that no decision had been made for the rest of the administration’s two months—but officials stopped short of saying the funds would be used before Bush leaves office.