Andrew Taylor, The Associated Press

WASHINGTON (AP) " The White House is finalizing a multi-billion roster of proposed spending cuts but is leaving this year's $1.3 trillion catchall spending bill alone.

GOP aides say the so-called rescissions package is arriving on Capitol Hill on Tuesday.

Pressure from party conservatives to increase cuts to as much as $15 billion contributed to a delay from Monday's original release date.

The project is backed by tea party lawmakers upset by the budget-busting "omnibus" bill.

It's also a priority for House Majority Leader Kevin McCarthy, R-Calif., who's taking the lead on Capitol Hill and likens it to "giving the bloated federal budget a much-needed spring cleaning."

McCarthy wants to succeed soon-to-retire House Speaker Paul Ryan, R-Wis., and some of his allies view the project as a way to improve his standing with fractious GOP conservatives who blocked his path to the speakership in 2015.

The proposal has already had a tortured path even before its unveiling. More pragmatic Republicans, including the senior ranks of the powerful House and Senate Appropriations committees, rebelled against the measure. They argued that it would be breaking a bipartisan budget pact just weeks after it was negotiated. In response, Mulvaney cleansed the measure of cuts to the huge omnibus measure.

Last month, Mulvaney told lawmakers the plan could have totaled $25 billion or so. Now, he says he's planning to submit several different packages of spending cuts " and it's likely they'll get more conservative with each new proposal.

Either way, the idea faces a challenging path in Congress, particularly the Senate, where a 51-49 GOP majority leaves little room for error even though budget rules permit rescissions measures to advance free of the threat of Democratic filibusters.

The aides required anonymity because they weren't authorized to speak publicly.