(Reuters) - Vermont’s senate on Wednesday passed a bill to legalize recreational marijuana use, which would make the state the first in the nation to do so through the legislative process rather than a ballot initiative.

FILE PHOTO: People roll a marijuana joint on the informal cannabis holiday, 4/20, corresponding to the numerical figure widely recognized within the cannabis subculture as a symbol for all things marijuana, on the Common in Boston, Massachusetts, U.S., April 20, 2017. REUTERS/Brian Snyder/File Photo

Republican Governor Phil Scott is expected to sign the bill, which passed the Democratic-controlled Senate by a voice vote. The Democratic-controlled House of Representatives passed the measure last week. Although Vermont is one of the most politically liberal states, it is also one of 23 in the nation that do not allow ballot initiatives.

The Vermont bill would allow those 21 and older to possess up to one ounce of marijuana, two adult plants and four immature plants beginning on July 1. It does not immediately clear the way for retail sales of the drug, leaving that up to a commission created last year to study how to tax and regulate it.

Passage would put the state directly at odds with the Trump administration. Last week, U.S. Attorney General Jeff Sessions reversed an Obama-era policy easing enforcement of federal laws banning the drug in eight states where it is legal.

“Vermont in particular doesn’t care very much what the attorney general thinks,” said Matt Simon, New England political director for the pro-legalization Marijuana Policy Project. “With the way this bill is written, having a few plants, there’s nothing that the feds could do even if they wanted to.”

Law enforcement groups in Vermont have criticized the legalization drive, saying the drug poses health risks and that there is no way to quickly test drivers who might be intoxicated by marijuana.

Neighboring Massachusetts, nearby Maine and six other states have legalized marijuana use as a result of voter initiatives.

New Hampshire’s House of Representatives on Tuesday passed a similar bill to legalize recreational marijuana use. That state’s governor, Republican Chris Sununu, has said he opposes legalization.

Marijuana advocates say that legalizing sales of the drug will help to phase out the existing illegal market and allow states to take in additional tax revenue.

Five of the first states to legalize the drug - Colorado, Washington, Oregon, Alaska and Nevada - together generated more than $485 million in tax revenue off marijuana sales in the first nine months of 2017, according to an analysis by the Marijuana Policy Project.