Texas Sen. Ted Cruz escalated his conflict with fellow Republicans Tuesday when he stepped up his attacks on President Barack Obama's signature health care law, complicating House GOP efforts to pass a funding bill that would avert a government shutdown next week.

Launching a marathon speech modeled on old-fashioned filibusters, Cruz also informed his Senate GOP colleagues that he would try to stretch the debate well into the weekend, according to senators who attended private huddles Tuesday. With Senate passage all but certain, including funds for the health law, senior Republicans had hoped to allow the measure to advance quickly to give House Speaker John Boehner more time to respond with a different version of the legislation.

Instead, the freshman senator took the floor Tuesday afternoon promising to speak until he was "no longer able to stand." His effort to block the legislation stood almost no chance of success, as the series of votes advancing it are locked in and most of his Republicans have abandoned him in the effort.