The rival party leaders on Capitol Hill are moving to avert any chance of a government shutdown this fall in advance of the presidential election, congressional aides said Monday.

Republican House Speaker John Boehner of Ohio and Democratic Senate Majority Leader Harry Reid of Nevada instead are likely to soon unveil a stopgap spending agreement that would keep the government on autopilot at basically current funding levels after the 2012 budget year closes on Sept. 30.

It's a tactical retreat for Republicans, who had sought to cut $19 billion below the budget agreement reached last summer with President Barack Obama and shift $8 billion more from domestic agencies to the Pentagon. Democrats had insisted on running the day-to-day operations of government agencies at the $1.047 figure in last summer's budget and debt accord.

To Republicans, the alternative of risking a government shutdown — just weeks before Election Day — was a nonstarter.

Reid had tipped his hand last week, saying his preference was for a longer-term stopgap measure that would take the issue off the table in a post-election lame duck session that's already facing lots of must-do legislation on taxes and averting tough, automatic spending cuts to the Pentagon, domestic programs and Medicare payments to doctors.

An agreement could be announced as early as Tuesday, aides say. They required anonymity because they were not authorized to speak on the record about the developments.

Despite costing more than many Republicans conservatives would like, many of them support the idea because it would avoid the chance that the lame-duck session would produce a foot-tall omnibus spending bill that would upset their tea party supporters. They're also looking for a better deal if, as they hope, likely GOP nominee Mitt Romney wins the White House and Republicans take back the Senate.