Supporters raise signs during a rally Monday in support of a bill to legalize medical marijuana on the steps of the state Capitol in Harrisburg. Sen. Mike Folmer, a sponsor of the bill, said he expects the Senate Appropriations Committee will send it to the floor next week.

HARRISBURG — Buoyed by the prospect of legislative action on a medical marijuana bill, dozens of supporters called for its passage at a Capitol rally Monday as Pennsylvania lawmakers returned from their summer recess.

Parents of sick children and patients with painful medical conditions spoke at the rally about the consequences of state laws that keep marijuana illegal. Many in the crowd held up placards with slogans like “Pills Kill” and “Campaign 4 Compassion.”

Sen. Mike Folmer, a prime sponsor of the bill, said he expects the Senate Appropriations Committee will send it to the floor next week.

The proposal has strong legislative support in both houses, possibly enough to override a veto by Gov. Tom Corbett, Folmer said. In that case, “the smart thing for him to do is just do nothing” and allow the bill to become law without his signature, the Lebanon County Republican said.

Corbett supports research and the use of a marijuana extract to treat severe seizures in children, but the governor opposes the medical marijuana bill as going too far in legalizing what he regards as a gateway drug.

Corbett’s spokesman Jay Pagni stopped short of saying his boss would veto the measure if it reaches his desk and declined to speculate about the prospect of it becoming law without his signature.

“The governor remains opposed to it,” Pagni said.

Twenty-three states have legalized medical marijuana, including all of Pennsylvania’s neighbors except Ohio and West Virginia.

Folmer’s bill would authorize doctors to prescribe marijuana to reduce pain and provide other relief for patients who are not helped by conventional drugs.

“What we have here is a heartless, cruel, irrational policy which is making people suffer and which is killing people and it has to stop,” co-sponsor Sen. Daylin Leach, D-Montgomery, said at the rally, referring to the current law.

The bill would allow the use of the whole marijuana plant. Smoking medical marijuana would be barred, but it could be used in other forms, including vapor, edible products and extracted oil.

“You can’t be against this and be for total privatization of liquor,” Folmer said, referring to Corbett’s ongoing campaign to get the state out of the liquor and wine business.