US lawmakers begin last-ditch effort on debt ceiling

Senate hurdles

Senate aides said the two leaders are looking at two possible ways of speeding the legislation through the chamber, which often can bog down for days with procedural hurdles.

Senator Dick Durbin, the second-ranking Senate Democrat, told reporters: "In order to move this quickly tomorrow or as soon thereafter as possible, we need cooperation of members. If they want to drag their feet, use every objection they can, this could take a few days."

Under one scenario, all 100 senators would agree to let Democrats schedule quick votes to pass the bill. That would mean that Tea Party firebrands, such as Republican Senator Ted Cruz, would give up their rights to delay a vote.

Cruz has not publicly announced his intentions but some Senate aides think that the Texas freshman with presidential aspirations has been sending positive signals in recent days.

Cruz and fellow Tea Party activists late last month delayed passage of a government funding bill as they demanded major changes to Obama's landmark healthcare law.

The deadlock led to federal agency shutdowns as Obama and his fellow Democrats stood firm against changing the law.

The other scenario would have the House send a formal "message" to the Senate to pave the way for quick Senate action, according to a Senate aide who asked not to be identified.

Again, it was not clear whether House Republicans would go along with that option.