All eyes are on the U.S. Congress and the effort to pass the Bush administration’s bailout package for the financial services industry. According to one Washington expert, the passage of some sort of package is likely, although some tweaks and arm-twisting will likely be needed first.

The latest news in the bailout bill saga is that the U.S. Senate has usurped the House of Representatives on this by crafting an alternative plan that adds sweeteners such as higher bank deposit insurance and tax cuts designed to get the bill passed. That plan will be voted on later today by the Senate, and if passed, must then go back to the House for approval.

On a conference call hosted by Sanford C. Bernstein & Co. LLC on Wednesday, Steve McBee, president and CEO of Washington, D.C.-based consulting firm, McBee Strategic Insight LLC, predicted that the revised bill will pass the Senate by a decent margin today. The bigger question, however, is how it will be received by the House. On that front, there’s a good deal more uncertainty.

Ultimately, McBee predicted that a bill will be passed, likely before the end of trading on Friday. However, he noted that there are plenty of risks to that outlook, primarily that the changes moved by the Senate aren’t yet attracting a lot of support from possible swing votes in the House.

Only 12 no votes have to be converted into yes votes for the bill to pass, but McBee said early indications are that those votes aren’t there yet. Although the tax cuts have been added to sway Republicans to support the bill, they may not be enough to get a lot of them to change their vote. Moreover, they could scare off so-called Blue Dog Democrats, fiscally conservative Democrats who supported the original bill, but fundamentally oppose these sorts of tax cuts. Also, the revised bill doesn’t include any sort of foreclosure relief that could have attracted further Democratic votes in favour of the bill.

On the positive side is a sense that voter opposition to the bill has softened in the face of the huge stock market drops that followed the bill’s rejection by the House on Monday; that may sway some reps to change their votes. Also, the action by the Senate to support a bill, which will likely include yes votes from both presidential candidates, puts pressure on the House to support it as well, McBee noted.

If the House leadership doesn’t appear to have the votes for this latest version of the bill, it will likely be modified yet again. McBee suggested that the bill won’t be put before the House unless its passage is certain. In that case, it would have to go back to the Senate, and then the president for final approval.

The bill remains an overriding concern for markets as the latest data out of the U.S. Wednesday continues to be weak. The ISM manufacturing index for September came in much weaker than expected, reported RBC Capital Markets. The weakness was relatively broadly based among the key subcomponents, it said, and the jobs component was also discouraging.

“This report adds to the pessimism about the near-term outlook for the economy already threatened by the recent tightening in credit conditions. However, the near-term course of monetary policy will likely be influenced by what happens to the rescue package currently before Congress,” RBC says.

“The initially proposed package provides sizeable funds to be made available to the government to address the illiquidity in many asset markets that are currently impaired, either directly or indirectly, by weakening sub-prime mortgages. Any moves on interest rates will await the fate of this package in Congress and an assessment of the effectiveness of the measures settled on to get financial markets functioning once again,” it concludes.