A long languishing bill that would require first-time drunken driving offenders to operate a motor vehicle only with an ignition interlock device got a boost Tuesday from the national leader of Mothers Against Drunk Driving.

The device prevents drivers from operating a vehicle if they have consumed alcohol. MADD’s president, Colleen Sheehey-Church, said supporters have been trying since 2008 to get Massachusetts lawmakers to approve the legislation.

“We don’t understand why it’s taking so long to pass a lifesaving bill,’’ Sheehey-Church said during a news conference in front of the State House.

“It is the easiest, fastest, most effective way to have somebody get into a vehicle and allow them to go on with their daily life, easy and sober,’’ she said.

The plan would replace hardship licenses, which allow some convicted drunk drivers to operate motor vehicles during specific hours while their regular driver’s license is suspended, according to MADD.

The devices, which require drivers to provide breath samples to activate their motor vehicles, are already mandated for repeat drunk drivers in Massachusetts, Sheehey-Church said.

Ann Marie and Don Laduzenski, whose son David, 29, was killed by a drunk driver in 2011 in West Springfield, are backing the proposal.

“It would, number one, put a defense between you and me. The person can’t drive drunk,’’ Ann Marie Laduzenski said. “They have to blow into this machine, and then it won’t start if he’s drunk. It would hopefully protect you and me from being killed.’’

Sheehey-Church said she and other supporters had 70 meetings planned for Tuesday at the State House. They met with staff members for House Speaker Robert A. DeLeo and Senate President Stanley C. Rosenberg.

In a statement, a spokesman for DeLeo said the speaker is awaiting a decision from the Joint Committee on Transportation, which is considering the bill. The committee has until next Thursday to act.

The committee chairmen, Senator Thomas M. McGee and Representative William M. Straus, did not respond to requests for comment Tuesday.

MADD said data collected from three device manufacturers found ignition interlock devices in Massachusetts prevented motorists with blood-alcohol levels of .08 or more from driving nearly 38,000 times between Jan. 1, 2006, and Dec. 1, 2015. The state’s blood-alcohol limit is .08.

Twenty-five states have laws requiring all motorists convicted of drunken driving, including first-time offenders, to use an ignition interlock device, MADD said. Maryland Governor Larry Hogan is expected to sign similar legislation soon, a MADD spokeswoman said.

“This is the best device, literally the best technology we have right now, to stop people from drinking and driving,’’ Sheehey-Church said. “License suspension just can’t do that. It’s not monitored.’’

Senator James E. Timilty, a Walpole Democrat who sponsored the bill, did not respond to a request for comment Tuesday.

Sheehey-Church said House lawmakers have indicated that some opponents worry the ignition interlock devices would prompt more motorists facing their first drunken driving case to seek a jury trial rather than settle the case with a plea.

Attorney Andrew DiCarlo Berman said requiring first-time offenders use an ignition interlock device is “draconian.’’ Berman is senior trial counsel at the law offices of Russell J. Matson, which specializes in drunken driving defense.

He said some motorists lose their jobs over ignition interlock devices because they drive company vehicles and their employers do not want to install the technology on their fleets.

“It does cause people to lose their jobs, and it’s more appropriate for a second offense or subsequent offense,’’ Berman said.

Laura Crimaldi can be reached at laura.crimaldi@globe.com. Follow her on Twitter @lauracrimaldi.