Boston - Citing the hefty sums of cash likely to be spent influencing future votes on casino proposals, the state's top elections official Wednesday called for a stronger system of monitoring spending on local ballot question campaigns.

"You don't have to be for casino gambling or against casino gambling," said Secretary of State William Galvin, in testimony before a legislative committee. "It's about disclosure."

Galvin urged passage of a bill requiring that all spending for or against casino proposals appearing on local ballots be reported to the state Office of Campaign and Political Finance, in the same manner that spending on statewide ballot questions must be reported.

Currently, spending on local ballot issues must only be reported to the clerk's office in the city of town where the vote is being held, and not until just eight days before the scheduled vote.

Galvin argued that casino proposals are unlike the property tax overrides or other questions that typically go before local voters.

"Most local ballot questions relate to issues that are very local in nature and where not that much money is going to be spent," he said.

By contrast, Galvin argued that millions could potentially be poured into casino campaigns to win over the hearts and minds of local voters, and the results of those votes would have repercussions well beyond a single community.

"It's important that voters know where the money is coming from," he said, adding that local clerks lack the resources of the state agency to enforce the law or spot possible discrepancies in campaign expenditure reports.

The bill would require a committee formed to support or oppose a casino referendum to file its first financial report with the state at least 60 days before a vote.

It was far from clear if the Legislature would act on the bill before the current session ends July 31, and lawmakers have shown reluctance to revisit aspects of the casino law they approved last year.

The law, which allows for up to three resort-style casinos in Massachusetts, requires that casino projects be approved by voters in host communities.

The bill would place no restrictions on casino referendum spending.