Legislative leaders are preparing to unveil their plans for removing the state’s religious exemption on mandatory vaccines, a hot-button topic that has provoked heated debate and brought hundreds to the Capitol to speak out against the move.

House Majority Leader Matthew Ritter, D-Hartford, said Wednesday that lawmakers are expected to make an announcement by the end of the week. He was tight-lipped about what method they might use to introduce the repeal with less than three weeks left in the legislative session.

The change would not force children to be immunized, but it would prohibit kids who are not vaccinated on religious grounds from enrolling in the state’s public schools.

At issue is whether children already enrolled in school would be “grandfathered in” as part of the legislation, meaning the repeal may only affect those looking to attend public school in the future. Lawmakers are also weighing whether to keep unvaccinated people out of day care centers and nursing homes.

“We’re working through it,” Ritter said. “We’re very close to an announcement.”

Earlier this week, hundreds flooded a hearing room and overflow spaces at the state’s Legislative Office Building to urge lawmakers to abandon their effort targeting the religious waivers.

Legislators originally had planned to introduce a repeal within a year, but sped up their efforts after reviewing school-by-school vaccination data released this month by Connecticut’s public health department. The data show 102 schools where less than 95 percent of kindergarten students were vaccinated for measles, mumps and rubella - the threshold recommended by the Centers for Disease Control and Prevention. Several schools recorded double-digit percentages for religious exemptions to vaccines.

Some people questioned why, in the absence of an emergency, politicians were pushing so hard to wipe out the provision.

Connecticut’s health department has reported three measles cases so far this year. Nationally, hundreds of cases have been recorded across more than 20 states. Health officials have called the outbreak the worst in the country in 25 years.

“We all define state of emergency differently,” Ritter said. “I think a lot of people feel that for a disease that was eradicated - three cases are a lot. It’s a public health emergency to react to one case.”

Some attendees at the public hearing threatened to move out of state. One asked for a show of hands on how many people would vote against lawmakers who supported the repeal. Hundreds raised their hands.

“I am not going to injure my child again with a vaccine. I will not do it,” testified Melissa Sullivan, executive vice president of the grassroots group Health Choice Connecticut.“It will be over my dead body.”

Legislators also heard from experts at the hearing, some who extolled the benefits of vaccines and others who did not take a position but testified to their importance for public health.

“If you achieve certain levels of vaccination in the population, you can actually provide protection for everyone,” said Matt Carter, the state epidemiologist.

People with knowledge of the plans said lawmakers would caucus on the issue late Wednesday. The legislative session adjourns June 5.