Convicted criminals in Victoria can receive compensatory sentence discounts for good behaviour in unforeseen circumstances, such as industrial disputes and lockdowns, known as emergency management days.
The only laws of their kind in Australia, those measures would be abolished if the state's opposition can depose the Labor government at the November election.
"Labor's freebie sentence reductions do not meet community expectations and are out of step with other states," opposition police and corrections spokesman Brad Battin said.
Collectively, nearly 2300 years were scrubbed from inmates' prison terms over a four-year period due to the scheme, according to Freedom of Information documents released to the coalition.
Those reductions were afforded to offenders, including killers, rapists and pedophiles, during the COVID-19 pandemic.
Prisoners were automatically handed four days off their sentences for every day of lockdown endured by Victorians.
Convicted murderer Shane Robertson, who brutally bashed his partner Katie Haley to death in 2018, had 14 months wiped from his sentence owing to COVID-era emergency management days.
Ms Haley's father and sister, Boyd and Bianca Unwin, have since led the campaign to scrap the controversial law.
"For two and half years we've lobbied the government to make changes, (but) even just to review it was knocked back," Mr Unwin said.
"When we got the email saying he was getting 427 days off, that just brought it all back."
The same time frame was sliced from a murder sentence granted to James Stoneham, who stabbed his 20-year-old former partner Adriana Donato to death with a hunting knife in 2012.
Celeste Manno's killer Luay Sako, who stalked his former colleague before smashing his way into her Melbourne bedroom and murdering her in November 2020, had already accrued 79 emergency management days at the time of his February 2024 sentencing.
Automatic granting of COVID-related emergency management days ended in February 2023, according to the Labor government, with prisoners now required to apply for them.
Labelling the coalition's pledge a straw-man policy, a Victorian government spokesperson said the coalition was "stuck re-litigating COVID".
"(Opposition Leader) Jess Wilson is fighting a COVID-era scheme that ended more than three years ago," they said.
"If Jess Wilson really cared about community safety, she'd explain how her 31,000 frontline job cuts won't gut our police, prisons, and courts."
More than 18,000 discounted days have been approved under the scheme since mid-2023, according to Freedom of Information documents.
"It's smoke and mirrors ... (the scheme) is there, we are proof that it's there," Mr Unwin said of the government's suggestion the discount strategy had ended.
Ms Wilson said the coalition would take advice about whether discount balances could be cleared retrospectively for prisoners still serving their sentences.
But convicted criminals who had returned to the community after serving reduced sentences would not need to return to prison, she said.
In 2021, the then-federal coalition government amended legislation to stop commonwealth inmates from accruing emergency management day credits in Victorian prisons and retrospectively repealed existing discounts.
