A Parliamentary Committee stacked with Palaszczuk Labor Government MPs has voted against supporting an LNP Bill to guarantee all convicted child killers spend at least 15 to 25 years behind bars.
LNP Deputy Leader Tim Mander said Labor shouldn't play politics with child killer laws.
"The LNP's Bill would deliver the toughest sentences in Australia for those who kill children through violence or neglect," Mr Mander said.
"The Committee instead recommended Labor's own weak legislation that doesn't go far enough to protect children and punish child killers.
"The LNP's Bill was drafted in honour of Caboolture toddler Mason Jett Lee, who died in agony over several days after being savagely beaten by his step-father.
"The LNP offered to work with Labor and support their bill if they supported ours as well, but Labor played politics with child killer laws."
Shadow Attorney-General David Janetzki said the LNP's Bill would introduce a new offence of child homicide, with a mandatory 15-year jail penalty.
The Bill would also increase the minimum non-parole period for the murder of a child under 18 from 20 to 25 years.
Mr Janetzki said the proposed child homicide offence would target those who kill through violence, sexual assault or neglect.
"In stark contrast to the LNP's strong laws, Labor's legislation is a tricky legal fix that will fail child victims," Mr Janetzki said.
"Without the LNP's proposed new laws, Queensland will continue to see weak sentencing for child killers.
"Annastacia Palaszczuk's tricky legal change hasn't worked in New South Wales and Queensland will be no different.
"Only the LNP will guarantee that child killers receive a minimum of 15 years imprisonment for manslaughter and 25 years for murder."