The Democratic leadership of the Massachusetts House of Representatives is set to release an overhaul of the voter-passed marijuana legalization law Wednesday, with the full 160-member chamber expected to vote on the bill Thursday.

What the rewrite will do remains opaque. Even though the Legislature’s committee on marijuana policy has been working on the issue for months and has held several public hearings, it has not yet released any draft language.

That’s unusual even by the secretive standards of the Massachusetts Legislature because lawmakers are tinkering with a ballot question passed by more than 1.8 million voters in November.