A crisis-conquering deficit-reduction agreement struck by the White House and congressional leaders after months of partisan rancor picked up momentum in the Senate Monday, as a member of the Republican leadership predicted at least 30 GOP votes.

Hours before a crucial vote, Republican leaders pleaded with their fractious rank and file Thursday to support a House plan to stave off an unprecedented government default. The vote would bring President Barack Obama and congressional leaders a step closer to endgame efforts before Tuesday's deadline.

Six days away from a potentially calamitous government default, House Republicans appeared to be coalescing Wednesday around a work-in-progress plan by House Speaker John Boehner to increase the U.S. borrowing limit and chop $1 trillion in federal spending.

Budget analysts said Wednesday that a Senate Democratic plan to reduce the deficit and increase the nation's borrowing authority would save $2.2 trillion over a decade, more than a rival House Republican proposal but less than promised.

GOP plan could provide leverage in forcing Democrats and President Obama to cut federal benefit programs.

House GOP leaders are planning a vote Thursday on a proposed amendment to the Constitution requiring a balanced budget.

House Speaker John Boehner predicted Thursday that a majority of House Republicans will end up supporting some kind of compromise as the Senate began debating a House-passed effort to tie an increase in the debt ceiling to conservative demands for a balanced budget amendment to the Constitution.

The Senate has taken up tea party-backed House legislation tying an increase in the government's borrowing authority to a series of conservative demands including a constitutional balanced budget amendment.