PORTLAND — Portland’s police chief has sounded a call for volunteers to help him collect the roughly 50,000 voter signatures needed to force a referendum next year on a proposal intended to keep guns out of the hands of children.

Chief Michael Chitwood says he plans to devote his off-duty time to the ballot question, the wording of which was approved Monday by Secretary of State G. William Diamond.

The signatures must be submitted to the state by next Jan. 24 in order for the question to appear on the ballot in November 1991.

The question reads: “Do you favor changes in the Maine law concerning holding an adult responsible if a child gains unsupervised access to an improperly stored firearm?”

Approval of the referendum would make it illegal for a person to recklessly store or leave a gun and not secure it in a way that would prevent children under the age of 16 from obtaining unsupervised access to it.

Maximum penalties under the law would be fines of $1,000 and a year in jail.