How likely is a government shutdown and who will be affected? What you need to know.

WASHINGTON−As House Republicans remain deeply divided on spending negotiations, the federal government barrels closer to a shutdown.

Congress has 10 days to pass necessary funding legislation or a stopgap measure to prevent thousands of Americans from being temporarily out of work and losing government benefits.

The last government shutdown was during the Trump administration and stretched for 35 days between December 2018 and January 2019.

Here's what you need to know about the possibility of another shutdown and who would be affected.

What happens in a government shutdown?

To avoid a shutdown, Congress must agree on crucial spending legislation and pass a federal budget by Sept. 30. They can also buy themselves more time with a continuing resolution, which would extend current funding and the deadline to pass a new budget.

If lawmakers are unable to do so by the end of this month, all federal agencies except those that are "essential" — including U.S. Postal Service, Medicare and Social Security — will stop work.

Even Capitol Hill is not spared: While lawmakers continue to work and receive pay through a government shutdown, tens of thousands of congressional staff will go without a paycheck for the duration.

Other consequences of a total government shutdown include furloughs for federal employees, delayed government food assistance benefits and national park closures.

How likely is a government shutdown?

With just over a week until Congress hits their deadline, the possibility of a shutdown grows day by day.

A handful of ultraconservative House Republicans are holding their ground over demands to stop what they call political "witch hunts" by the Department of Justice and FBI, along with "blank check" funding to Ukraine.

Lawmakers have begun exploring other options, such as a discharge petition, which would allow members from a bipartisan coalition to bypass procedures and Speaker Kevin McCarthy, R-Calif., to force a spending bill vote on the House floor. The measure would need approval from 218 members.

If no agreement or solution is reached in 10 days, a shutdown will begin on Oct. 1.

Will a government shutdown affect air travel?

Air traffic controllers will continue working during a shutdown, along with customs and border agents.

Passport applications may be halted, though. And without pay for working controllers or training for new FAA employees, the airline industry and travelers could still feel the impact.

This article originally appeared on USA TODAY: Here's what happens in a government shutdown and who is affected