Updated at 1:55 p.m.: to include mention of senators switching from opposition to support

AUSTIN — Only Gov. Greg Abbott’s signature is required for Texas to join more than a dozen states in requiring purchasers of cigarettes, e-cigarettes and other tobacco products to be 21 years old.

On Tuesday, the Senate agreed to House changes and sent Abbott a bill that would raise the legal sales age for such products from 18. The vote was 27-4.

Voting against were Republican Sens. Brian Birdwell of Granbury, Dawn Buckingham of Lakeway, Pat Fallon of Frisco and Angela Paxton of McKinney. Eight senators who voted against the bill on initial passage last month, including Republicans Bob Hall of Edgewood and Kelly Hancock of North Richland Hills, voted for it on Tuesday.

If Abbott signs Senate Bill 21, Texas would be the most populous Southern state to embrace so-called Tobacco 21 or “T21” legislation.

Rep. John Zerwas, R-Richmond, and Sen. Joan Huffman, R-Houston, the respective House and Senate authors of age bump measures, were cheered on by health advocates including the Campaign for Tobacco-Free Kids as well as a new ally — the nation's largest tobacco manufacturer, Altria Client Services, Inc., makers of Marlboro cigarettes and other products.

Two years ago, a similar proposal — then opposed by Altria — failed.

Also aboard: San Francisco-based Juul Labs Inc., whose e-cigarette cartridges account for more than 70% of U.S. e-cig sales. Last year, Altria acquired a 35% stake in Juul.

Helping ease passage, too, was an exception for young members of the armed services.

Initially, the Senate permitted “active” military ages 18 through 20 to buy cigarettes and e-cigs. On Wednesday, the House moved to exempt anyone in the military regardless of active status. As of March, according to the Pentagon, Texas was home to more than 17,800 members of the military aged 18 through 20, active and reserve.

This year, the T21 legislation also was viewed skeptically by owners of Texas shops that sell vape devices, which are pitched as helping conventional smokers step down their consumption of addictive nicotine.

In March, Kathleen Russell, a representative of the Smoke Free Alternatives Trade Association, unsuccessfully urged legislators to add a provision preventing local governments from imposing additional limits on e-cigarette sales.

“To allow local municipal governments to apply an endless array of city-specific restrictions or requirements on the legal products we sell would be like allowing cities to regulate the types of brands of alcohol sold in liquor stores — or the brands of beer sold,” Russell said in written testimony.

Russell added that, at the least, local governments should be barred from imposing an even higher age of sales — an idea the House later agreed to roll into the bill.

If Abbott signs the measure into law, Texas would join Arkansas, Maryland and Virginia among Southern states with laws elevating the age of sales to 21 — a change pitched by advocates as potentially driving down cigarette and e-cig consumption among students in middle and high school.

Eleven other states including California have Tobacco 21 laws, while New York’s legislature has sent a raise-the-age measure to Gov. Andrew Cuomo. It’s awaiting his signature.