Voting by mail and early voting would become permanent, and Massachusetts residents could register to vote on election day for the first time, under a bill the state Senate expects to pass next week.

Senator Cindy Creem's bill, which has the strong support of Democratic Senate leaders, would also require jails and prisons to inform inmates about their right to vote.

"At this time in our country's history, we know now more than ever how critical it is to ensure that all voices are heard in our democracy. And this bill embraces that ideal," Creem said at a State House press conference introducing the bill Thursday morning.

Senate President Karen Spilka said the bill emphasizes the Senate's commitment to increasing voting accessibility while other states attempt to limit access to the polls.

"It's just not simply enough to protect. We need to expand that access," Spilka said.

The legislation would order local prosecutors to investigate credible claims of mistaken or fraudulent voting, which in Massachusetts is exceedingly rare.

The full-throated backing of Democratic leadership all but guarantees the bill's passage in the Senate, but it's unclear if the House under Speaker Ron Mariano has any appetite to institute same-day voter registration. The measure would not be in effect for the November general election.