Lieutenant Governor Dan Patrick, increasingly desperate to pass legislation aimed at reforming the state’s property tax system, told a group of senators late Thursday night that if he can’t get the votes to win passage of the bill, on Monday he is simply going to change a decades-long Senate practice in order to guarantee himself a victory. Patrick issued the warning to Senate Democrats Thursday night, according to multiple sources familiar with the discussion.

To take up debate on legislation, three-fifths of the Senate, or nineteen senators, must vote to move forward. Patrick warned he would circumvent this so-called three-fifths rule, a move known around the Capitol as the “nuclear option” because it would upend decades of tradition in the upper chamber, a body that has long esteemed itself for decorum and consensus-building. Patrick’s apparent decision, supported by Republican leadership, to suspend the tradition on Senate Bill 2 would mean that only a simple majority—sixteen votes—would be necessary to pass the property tax bill.

“Property tax reform is my No. 1 priority. I need 19 procedural votes to bring a bill to the floor and we are one vote short. I respect our Senate rules, but I do not intend to let a procedural motion stop the Senate from passing this important bill,” Patrick said in a written statement. “If using the so-called ‘nuclear option’ is the only choice left to me to pass meaningful and lasting property tax reform and relief on Monday, as lieutenant governor I will lead as the public expects me to lead and exercise that option. The public doesn’t care about our procedural rules. They want tax relief and they deserve it. Time is running out on our session.”

The move has Democratic senators scrambling to fashion a response and has some Republicans concerned about the precedent that the move could set. Senators said they intend to work throughout the weekend to fashion a bill acceptable to both parties and thereby avoid the nuclear option.

“It underscores the seriousness of the situation,” said Bill Miller, a longtime lobbyist and Capitol watcher who could not think of another instance in which this legislative maneuver has been used.

Currently, the Senate works under a rule in which noncontroversial legislation called a blocker bill always stands ready as the first order of business in a legislative day. In this case, the blocker bill concerns county park beautification, Senate Bill 409 by Senator Bryan Hughes, R-Mineola. In order to bring up the legislation that the Senate really wants to debate, the sponsoring senator needs to get three-fifths of the senators to suspend the rules and move legislation ahead of the blocker bill.

Patrick told a group of senators late Thursday night that he will temporarily do away with the three-fifths rule on Monday and place Senate Bill 2 as the first item on the day’s agenda.

Use of the blocker bill has been a staple of the Senate since at least the 1940s—a point of pride for senators. The practice has been employed to encourage compromise and bipartisanship. Until 2015, the rule was even stricter: two-thirds of the Senate, or 21 senators, had to vote to move the blocker bill, but Patrick, a critic of the rule since he was a freshman legislator in 2006, watered down the requirement to a three-fifths rule during his first term as lieutenant governor in 2015.

Patrick has had difficulty getting enough support for SB 2, which would place a 2.5 percent cap on how much a government entity’s property tax revenues could increase year over year before triggering an election requiring voter approval to raise their taxes. Many senators who are critical of the 2.5 percent cap said they are amenable to a 4.5 percent cap, but Patrick so far has held firm, drawing the consternation of many of the state’s mayors and county judges, who argue that the policy is draconian and would inhibit the ability of local governments to provide services to Texas’ rapidly growing population.