SALEM — Lawmakers moved a step closer Wednesday night to tightening regulations on Oregon’s medical marijuana program, despite vocal opposition from some people in the medical pot industry.

The legislative committee tasked with implementing Oregon’s new recreational marijuana system voted to include a proposal to limit the size of medical pot grows in a bill that could come up for a vote as soon as Monday.

Amendments added to the bill Wednesday also call for the state to track medical cannabis, impose residency requirements on growers and allow regulators to inspect medical cannabis gardens. The amendments passed Wednesday night include a provision that specifies patients only growing marijuana for personal use would not be subject to inspections.

Lawmakers want to rein in the medical system ahead of the launch of legal recreational pot July 1, because medical pot has been diverted into the black market. They originally planned to hold a vote Wednesday night on whether to move the bill out of committee, but they pushed that vote off until at least Monday after they received hundreds of phone calls and emails from people concerned about the proposed changes.

Although committee co-chair Sen. Ginny Burdick, D-Portland, said earlier in the week that lawmakers had already vetted and held hearings on every element of the legislation, the committee changed course and took testimony from lobbyists and other representatives of the cannabis industry and local governments.

“We have one more chance if there are further tweaks,” Burdick said Wednesday night. “Our plan at this time is to move the bill out (of committee) on Monday.”

Jonathan Manton, a lobbyist for Oregon SunGrown Growers Guild and political action committee, described his clients as “family farmers” who are “patient driven” and “very distrusting of government, as a lot of us are.” Manton said the growers he represents want the ability to charge patients for all of the costs they incur including labor, something that is not currently allowed but would be under the new proposal. The growers oppose limits on the size of marijuana gardens.

Lawyer Amy Margolis, of Oregon Cannabis PAC, described bill as amended Wednesday night was a good piece of legislation because of changes such as the allowance for growers to charge for their labor and other costs they cannot currently recover. Margolis said her group also supports a provision in the bill that would prevent cities and counties from taxing marijuana and regulating medical pot, except for reasonable restrictions on the time, place and manner of retail sales.

“We hope that part stays in here,” Margolis said.

Rob Bovett, a lawyer and lobbyist for Association of Oregon Counties, asked lawmakers not to preempt local regulations on marijuana businesses. Bovett said other states with legal marijuana have opted against such preemption provisions because it reduced the chances that local governments would challenge pot laws in federal court.

Anthony Johnson, chief petitioner and co-author of Measure 91, said he hopes lawmakers will slowly phase in the proposed limits on the size of medical marijuana grow sites.

The amendments added to the bill Wednesday would limit growers at sites registered with the Oregon medical marijuana program after Jan. 1, 2015 to 12 plants in residential zones inside cities and 48 plants per garden in other areas.

The amendments would grandfather in higher limits for grow sites already registered in the Oregon medical marijuana program on Jan. 1, 2015. They would cap the size of these gardens at 24 plants in city residential zones and 96 plants at all other areas, both rural and urban.

That is double the number of plants that would have been allowed at medical grows under the most generous bill lawmakers had previously considered, which would have allowed pot gardens with up to 48 plants outside city limits.

The Capital Bureau is a collaboration between EO Media Group and Pamplin Media Group.