The House on Friday hurtled toward a pivotal vote to keep the government open past Saturday, as Speaker Kevin McCarthy plunged ahead with a long-shot bid to pass a temporary spending bill that lacked support even from his own party.

The effort was all but certain to fail given the opposition of several hard-right Republicans who have said they will not back a stopgap spending bill under any circumstances. There was a chance that the rebels would relent and allow the measure to pass, but in the run-up to the vote, they showed no signs of budging.

Mr. McCarthy, bracing for political blowback for a government closure, scheduled the vote anyway in hopes of showing he was trying to avoid the crisis.

In fact, the measure under consideration, which would keep government funding flowing at vastly reduced levels and impose stringent immigration restrictions demanded by conservatives, would not prevent a shutdown even if it could pass the House, because it was considered dead on arrival in the Democratic-controlled Senate.

Mr. McCarthy cleared a key hurdle at midday Friday, when the House voted, along party lines, to bring the stopgap bill to the floor. That cleared the way for a debate and vote on the stopgap spending plan by early afternoon.

Here’s what else to know:

• Mr. McCarthy’s allies have defended his strategy as a way to show the public that he tried to keep the government open, but was foiled by a handful of his far-right members. A defeat on the House floor would be a devastating blow for Mr. McCarthy, whose job is on the line and who has been unable to corral his tiny majority to agree on a measure to head off a meltdown. “We’ll see when the vote comes,” he said on Friday morning, conceding the outcome was uncertain.

• The plan offered by House Republicans would keep the government open for 30 days and impose drastic cuts across the board to government programs, except for funding for veterans, homeland security and disaster response. It does not include any military or humanitarian aid for Ukraine, and it would direct the homeland security secretary to resume “all activities related to the construction of the border wall” at the southern border that were in place under former President Donald J. Trump.

• Even if the House stopgap measure passed, it is considered dead on arrival in the Senate, and Mr. Biden would veto it, his Office of Management and Budget said in a statement.

• If the House is unable to pass any sort of temporary funding measure, it would be in an exceedingly weak position to negotiate with the Senate, which is moving ahead with its own, bipartisan short-term funding plan. That bill would continue spending at current levels for six weeks and provide $6 billion in aid to Ukraine and $6 billion for natural disaster relief at home.