With just a few weeks left to improve their gloomy electoral outlook, House and Senate Democratic leaders cannot or will not say exactly when they are leaving town, nor what exactly they will be voting on before they release their Members to the campaign trail.

A vote on extending Bush-era tax cuts that affect the middle class is one possibility. But Democratic leaders have not convinced their Members it is a winning move.

As a result, Senate Democrats could have a big hole in their agenda this week if they lose today’s vote to start debate on the Defense Department authorization bill. After all, they have yet to produce a bill to extend tax cuts for those making less than $250,000 a year, because some Members are not sure they even want to have that debate before the election.

To buy some time on tax cuts, Democrats are holding out hope that enough Republicans will vote to proceed to the defense measure, which includes a repeal of the military’s ban on gay service members. Majority Leader Harry Reid (D-Nev.) has indicated the defense authorization debate could start now but finish during the lame-duck session following the elections.

Meanwhile, House Democrats are barely showing up for work this week — arriving Wednesday evening and leaving Friday — as they wait to see what the Senate does on tax cuts.

“Neither one of the bodies want to be the only ones to vote on this,” a senior Senate Democratic aide said of the tax-cut measure. The aide suggested that both chambers were biding their time before trying to pass a continuing resolution to keep the government funded through the elections. The House passed two of the 12 annual appropriations bills this year, while the Senate took up none. Funding expires Sept. 30.

A senior House Democratic aide agreed that both chambers want to avoid being blamed for voting to let taxes rise on upper-income taxpayers on the chance the message is not a winner with voters after all. In fact, many House Democrats think the Senate should let Republicans filibuster or “hold middle-class tax cuts hostage,” as many Democrats have put it, and the House should go home without voting on it, according to another House Democratic aide.

That scenario appears increasingly likely as House aides focused on the timing for a vote on the CR. When the CR passes, the House will leave town, aides said.

But the prospect that the House may not vote on the Bush tax cuts is fueling some of the anxiety among rank-and-file Democratic Senators, the senior Senate aide said.

Senate Democrats may not have a choice in the matter. Under the rules, Minority Leader Mitch McConnell (R-Ky.) could easily file a motion to end debate, or invoke cloture, on his nearly $4 trillion bill to extend all Bush tax cuts, permanently fix the alternative minimum tax and make changes to the estate tax.

Another senior Senate Democratic aide said McConnell’s trump card, regardless of whether he uses it, may cause Reid to try to control the debate before it gets to that point. If that happens, Reid is likely to set up the tax-cut debate for next week, the aide said.

“He’s warned [Members] repeatedly that the debate is coming, so we might as well deal with it on our terms,” the second senior Senate Democratic aide said. The aide added, “Most of the heartburn is coming from the House.”

Indeed, House aides point out that just because a few national polls have indicated majority support for President Barack Obama’s plan for middle-class tax relief, some Democrats have found substantial opposition in their districts.

“District-by-district polling does not look good across the board,” another House Democratic source said. “It isn’t about nervous Nellies. It is about Members knowing what works for their districts and not.”

Though some Democrats want to dodge the debate altogether, Republicans could be at risk, too. That may explain why Senate GOP leaders refuse to say whether they would use their power to force a vote on the floor before the elections.

Asked Monday whether McConnell would employ that tactic in order to get Democrats to vote against tax cuts, the Minority Leader’s spokesman declined comment on the grounds it would reveal too much of the GOP’s strategy.

While a vote on just McConnell’s bill could be advantageous for Republicans, Democrats would no doubt respond by compelling a vote on a bill to only extend middle-class tax cuts. That would open up Republicans to accusations of voting against the middle class or implicitly endorsing a tax increase on those making more than $250,000 a year.

Meanwhile, leaders have not committed to a firm departure date in either chamber. Though Reid has repeatedly held out Oct. 8 as the Senate’s adjournment date, he has privately acknowledged it may be difficult to keep people in town past the end of next week, one Senate source said. And Speaker Nancy Pelosi (D-Calif.) does not appear to want to keep her Members in town a moment longer than needed, as evidenced by this week’s schedule.