WASHINGTON — A last-gasp effort today to avoid automatic tax increases and spending cuts got off on the same convulsive, partisan tone that marked congressional attempts to resolve the impasse before lawmakers headed home for Christmas.

With a Dec. 31 deadline for an agreement to avert the so-called “fiscal cliff” rapidly approaching, leaders in each party demanded the other side take the initiative. The new flare-up happened despite a round of calls President Barack Obama made to congressional leaders by phone Wednesday night from Hawaii before he boarded Air Force One to head home from vacation.

In a potential sign of movement, Republican leaders planned to bring the House back into session on Sunday evening. But what legislation they would act on, if anything, remained unclear.