First of three parts
BOSTON – Conflicting proposals from state lawmakers to implement the recreational marijuana law voters passed last fall has left Massachusetts cities and towns struggling to cope with confusion, and calls into question whether the regulated industry will be in place by next summer.

And that’s before lawmakers deal with signals from Washington, D.C., that the Trump administration may enforce an overall federal ban on marijuana sale and use.

The state legislature’s Joint Committee on Marijuana Policy and the treasurer’s office are leading the effort to figure out regulation, structure and methods to set up the framework before July 2018.

The November ballot question that supports taxing and regulating marijuana passed with about 53 percent of the vote. The measure allows adults older than 21 to smoke, purchase and grow some marijuana at home.

“There’s a lot of people (who are) very, very interested and have a variety of opinions and a variety of facts,” said Sen. Patricia Jehlen, who co-chairs the Joint Committee on Marijuana Policy. “We’re trying to understand some things, but we are trying to stick to the will of the voters and make any adjustments that are necessary.”

Jehlen, D-Somerville, has supported legalization while co-chair Rep. Mark Cusack, D-Braintree, has declined to say how he voted for the measure.

Gov. Charlie Baker, House Speaker Robert DeLeo, Attorney General Maura Healey and Boston Mayor Martin Walsh were against marijuana legalization while Senate President Stanley Rosenberg supported it.

Since mid-December, adults in the Bay State have been able to possess and use marijuana, but not sell it. Shops were initially scheduled to open in January 2018.

The Department of Revenue estimates that the state could reap up to $172 million in annual tax revenue from recreational marijuana sales.

Buyers would have to pay the state’s 6.25 percent sales tax and an additional tax of 3.75 percent, which is lower than rates in other states with legalized marijuana. Municipalities also can choose to tax 2 percent on top of sales and excise taxes.

Conflict between regulation, legislation