WASHINGTON — Two prominent old-line Senate Republicans threw down the gauntlet to their more conversative colleagues on Tuesday, challenging them to stop obstructing the passage of a budget.

Led by tea party Sens. Rand Paul (R-Ky.), Ted Cruz (R-Texas) and Mike Lee (R-Utah), Republicans have been preventing the Senate from sending the budget it passed earlier this year to a conference committee with the House, at which major differences between the two chambers’ budget bills would in theory be worked out. Senate Minority Leader Mitch McConnell (R-Ky.) has been supportive of the blockade.

But on Tuesday, Sens. John McCain (R-Ariz.) and Susan Collins (R-Maine) blasted the obstruction in a Senate floor showdown with Paul.

McCain went so far as to call his fellow senators’ actions “bizarre.”

More: John McCain, Susan Collins Oppose ‘Bizarre’ Rand Paul, Ted Cruz Demand