Kristina Keneally will take her seat in Federal Parliament as soon as next week, after a key factional meeting unanimously endorsed her to replace disgraced senator Sam Dastyari.

The former NSW premier-turned television host has told Labor officials she will make stillbirth research funding and constitutional recognition for Indigenous Australians a personal mission during her time in the Senate.

In a letter to the party's powerful Right faction, Ms Keneally also heaped praise on trade unions as the "ballast" of the Labor movement and said social justice sat "at the heart" of her activism.

Former NSW premier Kristina Keneally will become a federal senator. Credit:Alex Ellinghausen

"I believe our society is most healthy when our most vulnerable members are supported, protected and included: people with a disability, their families and carers; babies and children; and older people and pensioners. I will always put their needs at the centre of my work.