The state Labor party's administrative committee met on Monday evening in Brisbane with both Mr Miles and Ms Fentiman angling for the support of their colleagues in light of Premier Annastacia Palaszczuk's shock resignation.
Mr Miles was endorsed by the outgoing premier in an emotional final press conference on Sunday.
The three-term leader was the final COVID-19 era state leader in Australia.
Ms Palaszczuk will formally tender her resignation to the Governor on Friday, with the Queensland Labor caucus set to gather and endorse a new leader that day.
Ms Palaszczuk will formally tender her resignation to the Governor on Friday. (Jono Searle/AAP PHOTOS)
Mr Miles is believed to have support from the biggest group in Labor's dominant left, the United Workers Union.
But Ms Fentiman said she wouldn't be stepping up if she didn't have "significant support", adding that she would back whoever wins the leadership vote.
A contested leadership ballot could drag on for weeks and under party rules, it would be split between elected MPs, rank and file members and affiliated unions.
But Treasurer Cameron Dick - from Labor's right faction - may play a role in avoiding that scenario.
He reportedly met with both Mr Miles and Ms Fentiman on Monday to hear their pitch for the top job amid speculation he'll back the most convincing candidate on a joint ticket.
Mr Miles said he hopes to deliver a better and more focused government in the lead-up to the October 2024 state election.
However, he faces stiff competition from the health minister who believes she is best placed to lead a government of "renewal" into the October poll.
Mr Miles said a Labor government he would lead will build on the three-term legacy championed by Ms Palaszczuk that refocuses the state "on the services Queenslanders rely upon".
Ms Fentiman said the government needs a fresh approach and believes she is the most suited to harness that in the top job.
"Labor MPs know me, they know my track record of bringing people together, of listening and delivering," she said on Monday.
"We need a refreshed approach, a government with fresh ideas and energy, one anchored in Labor values with robust cabinet processes.
"That's the kind of government I want to show Queensland in the year ahead."
