New AM Jack Sargeant has vowed in his first Senedd speech to ensure inquiries ongoing into the first minister’s conduct will examine how his father was treated in the run-up to his death.
The 23-year-old successfully held Carl Sargeant’s Alyn and Deeside seat for Labour in a by-election last week.
He said he knew he was not the only AM “who wants justice for my father”.
Carl Sargeant was found dead four days after he was sacked by First Minister Carwyn Jones in November.
The former cabinet secretary for communities and children had also been suspended from the Labour Party amid allegations of inappropriate conduct towards women, which he denied.
It is thought he took his own life.
A QC-led inquiry is due to get under way into the first minister’s handling of the sacking.
A separate investigation has also begun into claims that Mr Jones misled the assembly when answering questions about alleged bullying within the Welsh Government in 2014.
“I said last week that the by-election was one which no-one wanted to see,” Mr Sargeant told AMs on Tuesday in his first Senedd speech, with the first minister sitting nearby.
He said: “I know I am not the only person in this chamber who wants justice for my father.
“I know from the campaign we have just conducted that this feeling is also shared by my constituents in Alyn and Deeside.”
Wearing his father’s tie and tie-pin, he said he would work “to ensure that the inquiries under way will examine the way in which my dad was treated in the run-up to his death”.
“I owe my family, my constituents, my friends and my father no less,” he added.
Analysis by BBC Wales political editor Nick Servini
New assembly members traditionally pay tribute to their predecessors but when that person happens to be your father it adds a layer of emotion to proceedings.
As well as the tributes, there was also plenty about manufacturing in north east Wales, which is clearly what Jack Sargeant wants to champion in his new role.
But in the short term at least, he will pack the biggest punch when he speaks about the inquiries into the death of his father.
He has touched on this territory before, including in his victory speech at the count in Alyn and Deeside, but to do so in the chamber within a matter of feet of the first minister made this uncomfortable viewing.
That said, I am told from both sides that the two men had an amicable discussion under the circumstances in a meeting alongside the Economy Secretary Ken Skates.
In his speech Jack Sargeant paid tribute to his father, calling him the “glue that held our family together”.
“My dad truly loved the community and the people of Alyn and Deeside. He loved the sense of togetherness,” he said.
“Our community’s problems are everyone’s problems, and that’s clear by the way local people come together when times get tough.”
“We are of course devastated beyond words,” Mr Sargeant said, “and we know our grief has and will continue to be shared by all those who knew and loved him.
“I hope that as the representative of a new generation in this assembly, I can do something to build a better, kinder politics for the future,” he added.
Mr Sargeant was applauded by AMs in the chamber at the beginning and the end of his speech.
Earlier, he met the first minister for the first time since the death of his father at the weekly gathering of Labour AMs.