The significant increase in the number of women dying in Victoria last year is “devastating but not surprising”, according to the CEO of Domestic Violence Victoria.

Last year 18 women died in Victoria from probable or possible homicide, the statistics released by the coroners court on Wednesday show.

This is a significant increase compared with 2015, when 11 women died from murder or manslaughter. The probable and possible homicides of children fell slightly, from 11 in 2015 to seven in 2016.

“These deaths are absolutely tragic,” Fiona McCormack told Guardian Australia. “It is really devastating, but it is not necessarily surprising given the work we know is required to strengthen the web of accountability around men who are a risk to others.”

While the former Australian of the year Rosie Batty and Victoria’s royal commission into family violence had helped to raise awareness of the issue nationally last year, McCormack said it would take much longer for this to result in a reduction in deaths.

“We are alive to the reality that this is a very complex issue and it’s going to take time to prevent it, and to build a more sophisticated system to respond violence when it happens,” she said. “We also have long-term cultural work to do to change the attitudes that allow violence to flourish.”

Commitment from all political parties and opposition leaders was a key concern for Domestic Violence Victoria, McCormack added. While the Victorian government had committed to implementing all 227 recommendations from the royal commission, some of those recommendations could only be fulfilled through action by the federal government and would need long-term commitment from successive state governments.

“We would hate to see a commitment to addressing violence against women go backwards with a change of government,” McCormack said. “That’s why this has become such a complex issue, because it hasn’t been tackled in a fulsome way in the past. But it should be the number one issue for all governments, given the number of deaths.”

Victoria’s victims of crime commissioner, Greg Davies, responded to the figures by calling for a mandatory life sentence for anyone who killed a child, describing them as “mongrels” on radio station 3AW in Melbourne on Wednesday.

“If you take away, on average now, more than 80 years of someone’s life, it’s a fair and reasonable assumption, from many in the community, that you should forfeit your liberty for the rest of your life,” he said.

The deputy premier, James Merlino, told reporters the figures were horrific and described the deaths of women and children as a result of family violence as “the most significant law-and-order issue facing our nation”.

But the government had no plans to introduce mandatory life sentences for those found guilty of murdering children, he said.

“These are absolutely heinous crimes and they already can carry a life sentence,” he said.