House and Senate leaders continue to work on a stopgap spending bill to close out the year, and could announce it as early as today. The bill would extend a continuing resolution on the budget for six months, until the end of March 2013. The spending levels would likely equal those designated in the debt limit deal, at $1.047 trillion, above what House Republicans offered in the budget resolution they passed earlier in the year.

But instead of reaching agreement and immediately securing passage, a common display in Congress, the leadership wants to nail down a resolution and then go out of town for five weeks:

Congressional leaders will not move this week on a stopgap measure to extend government funding for six months, leaving lawmakers a narrow window in September to avert a government shutdown before the election.

Republicans and Democrats have been discussing a funding bill in recent days, but aides said Monday it would not be unveiled before lawmakers head out of town for a five-week recess at the end of the week [...]

Aides say appropriators are waiting for technical budget data from the administration and Congressional Budget Office that is coming in August to write the spending measure.

The need for data to write the stopgap spending deal is understandable to an extent. But this just gives outside groups, particularly on the conservative side, five weeks to whip up opposition to a deal that uses spending levels they oppose. Five weeks is an eternity, and while the election year may mean that the focus will shift elsewhere, I could see a Freedom Works or Club for Growth make it a priority to stop the stopgap.

The fact that House conservatives have essentially blessed this process makes the prospect of a revolt less likely. But stranger things have happened. And one demand of a particular rider – say, the Keystone XL pipeline – could throw this all into chaos.

In other Congressional news, hopes for a one-year stopgap farm bill faded yesterday, as lawmakers may simply act to bring disaster relief to drought-stricken farmers in a standalone bill. This would mean that the farm bill would linger, and after September 30 farm programs would revert back to an obsolete 1949 standard.