Joan Burton said she would like to see more members of state boards appointed through the public appointments system.
The bookies' favourite to become party leader next week was reacting to news that a Labour party by-election candidate and a former Fine Gael TD have been added to the board of Bord na Mona.
The move was approved at cabinet by Labour's Pat Rabbitte, as Communications Minister.
His party colleague Joan Burton defended one of the appointees this morning, but said she would like to see this done more often through the public channels.
"I have approached the appointments I've made - and they've been few enough - via the public appointments service."
However, she said there had been an occasional exception.
"For instance, someone who was well-known as a whistleblower in relation to the banking, I specifically sought a go outside," she said.
"I know one of the individuals who is an absolutely committed environmentalist - I understand that he will serve on this board without payment."