As is common ahead of pending lapses in agency funding authority, policy and funding issues have brought the government to the brink of a partial shutdown that would begin Saturday.

This time, the main issue is the administration’s request for money to build a wall on the southern border, a proposal that congressional Democrats have said they will not support. However, some support from Democrats may be needed to reach any resolution on the budget, since a large bloc of Republicans in the House are threatening to withhold their votes as leverage over various issues.

The White House has insisted on added border-related funding, although it has signaled that it may agree to devote those funds not to construction but rather toward detection technology and hiring more patrol agents. Democrats in turn have signaled that they may agree to a compromise along those lines. The result could be to set the stage for a similar showdown in the fall over whether to put construction money in the budget for the new fiscal year starting in October.

Controversies over revamping health insurance and tax policy, as well as political issues of who would take the blame for a shutdown, also are in play. Such issues complicate the process of reaching the common final result of simply continuing funding at current levels with relatively minor changes for the remainder of the fiscal year.

That remains an option, but another frequently used maneuver also is on the table: buying more time. Such extensions typically are for short periods and are used when a resolution to the underlying disputes seems to be in sight.

One possibility would be a one-week extension, through May 5. However, because the House is scheduled to be in recess the following week, a longer delay, possibly through the Friday of its next week back at work, May 19, is another option.

Regardless of their design, shutdown-related bills commonly are not enacted until nearly the last minute.

Another outcome that has occurred in the past–although not for more than two decades–is to allow the shutdown to happen, with Congress continuing to work through the weekend so that it ends by the start of the new work week, either with a long-term solution or a short-term delay. That would lessen the impact since many federal operations that would be closed in a shutdown are not open on a weekend anyway, but still cause anxiety in the workplace.