Senate Majority Leader Harry Reid has laid the groundwork for a Monday vote on the contrinuing resolution to fund the government through September 30.

But fierce maneuvering by senators opposed to the measure blew up Reid's and Minority Leader Mitch McConnell's plans to adjourn for the weekend.

There is a two-track opposition to the spending bill.  Senator Ted Cruz is demanding a vote on an amendment that would block the president's immigration executive orders by defunding agencies responsible for implementing it.  And Senator Elizabeth Warren wants language that would allow Wall Street to recoup some losses from derivatives excised from the bill.

Neither measure has majority support – yet.  But if either amendment passes, the budget deal will blow up, and the government will be forced to curtail its activities.

CNN reports on some of the maneuvering:

The Senate was expected to vote Monday on the $1.1 trillion package, which has already passed the House, Sens. Mitch McConnell and Barbara Mikulski said late Friday.

Sen. Majority Leader Harry Reid had made a procedural move to set up a vote on final passage in the Senate no later than Monday.

McConnell, the incoming Senate majority leader, had reached a deal with Reid to adjourn for the weekend and resume Monday to clear the bill.

Late-night maneuver

But in a surprise development, some of McConnell's junior members defied the agreement after he left.

Reid tried to get unanimous consent for an adjournment until Monday when there would be enough votes to end a filibuster, but Sen. Mike Lee, a Republican from Utah, objected because Reid would not guarantee a vote on an amendment dealing with immigration funding.

Republican Sen. Ted Cruz of Texas also joined the objection, forcing the Senate to meet on Saturday.

Reid then announced to an almost empty chamber that the Senate will be in session beginning at noon Saturday.

It's unclear whether both sides will speed things up enough for a vote on the spending package over the weekend.

Will the government keep operating?

The Senate was facing a Saturday deadline to approve the spending bill and avert a government shutdown, but that was pushed back.

Earlier Friday, the House approved a five-day stopgap bill to make sure the government was continually funded. To keep the government operating, the Senate is expected to approve a five-day continuing resolution on Saturday.

The chamber has been sifting through many of the same arguments that tied up the House on Thursday, when disagreements over immigration and provisions related to Wall Street and campaign finance nearly derailed the bill. Senate lawmakers wanted votes on amendments that would address those issues.

Two votes are expected Monday: a procedural vote to block filibuster and end debate on the bill, and a second one on the final passage.

There's not much chance that the Cruz amendment can get the 60 votes necessary to avoid a filibuster.  But Warren's Wall Street amendment might have a chance.  It would probably need some GOP support to make it, but with Senator Vitter co-sponsoring the bill, a few Republicans might bolt and join the liberals.

Nancy Pelosi and Warren are making the Wall Street issue a litmus test for Democrats – and their base is responding enthusiastically.  But President Obama has finally come off the sidelines and endorsed the House version of Cromnibus, making Warren's quest a lot more difficult.

It's uncertain whether House Republicans are wedded to the Wall Street derivative language, and they could vote for a final Cromnibus bill without it.  Nor is it certain that Senate Democrats, if stymied in their effort to take out the offending Wall Street goodie, would vote for the package anyway.  And some conservatives might not vote for Cromnibus if the immigration funding remains.

Reid and McConnell have their work cut out for them if they want the spending bill passed.