/ Updated  / Source: Reuters

Texas' lieutenant governor on Wednesday threatened to push for a special legislative session if state representatives do not pass a measure that would limit bathroom access for transgender people before the current session ends on May 29.

The move by Republican Dan Patrick, who sets the legislative agenda in the state Senate where the bill was approved, comes as he is trying to gain the upper hand with the House over budget and tax policy positions.

"Patrick is using this more as a bargaining position than as a fresh line in the sand," said Mark Jones, a professor of political science at Rice University in Houston.

Lt. Gov. Dan Patrick speaks at the Republican Party of Texas State Convention at the Kay Bailey Hutchison Convention Center, Thursday, May 12, 2016 in Dallas.Rodger Mallison/Fort Worth Star-Telegram / TNS via Getty Images

The so-called "bathroom bill" is similar to one enacted last year in North Carolina. The North Carolina law prompted economic boycotts and the loss of sporting events, with critics saying it promoted discrimination against lesbian, gay, bisexual and transgender (LGBT) people. The state has since rolled back the restrictions.

The Texas measure, called Senate Bill 6, passed the Republican-controlled Texas Senate on a party-line vote in March but has languished in the Republican-controlled House.

It would require people to use restrooms in public facilities that correspond with the gender on their birth certificate, not the gender with which they identify.

Patrick defended the Texas bill in a news conference at the Capitol, saying: "This has never been about discrimination. It is about common sense, common decency and public safety."

Related: Transgender Bathroom Bill Fails in Tennessee Legislature

Republican House Speaker Joe Straus, whose San Antonio district stands to lose its right to host next year's NCAA Final Four men's basketball championship if SB 6 becomes law, has shown little support for the bill, saying it could damage the state's reputation and economy.

Republican Governor Greg Abbott has the authority to call a special session of the legislature, which holds regular sessions once every two years. Patrick could pile pressure on Abbott by halting a measure currently in the Senate that allows several state agencies to continue functioning.

Jones, the political science professor, said many Republicans understand that enacting the bathroom bill would tarnish the state's image as it tries to attract new business, and the lawmakers would like to see it die quietly when the current session ends. But if put on the spot, the same lawmakers would likely vote for it because they would be vulnerable to conservative challenges in Republican primaries if they did not, he said.

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