Third minister steps aside, leaving more options for Labor reshuffle

Ms Brown is stepping down from her ministerial duties for health reasons, but will remain in Parliament.

This will leave three positions in the Albanese ministry vacant, after ministers Brendan O'Connor and Linda Burney announced their retirements on Thursday.

There are reports NT senator Malarndirri McCarthy will take on Ms Burney's portfolio of Indigenous Australians and NSW senator Jenny McAllister will move into cabinet, in a reshuffle the Prime Minister is expected to confirm on Sunday.

Speaking in Canberra on Saturday, Finance Minister and ACT senator Katy Gallagher said the caucus was sending its support to Ms Brown, who is nicknamed "The Godmother" by her federal colleagues. It's understood she is undergoing treatment for cancer.

With all three retiring ministers on the left, it is likely their replacements will also be from the same faction, to continue Labor's balance between its major factional components.

Mr Albanese will also have to balance between the different states in his ministry.

There has also been speculation Home Affairs Minister Clare O'Neil and Immigration Minister Andrew Giles could be moved to new portfolios, while Queensland senator Murray Watt may shift from his agriculture portfolio.

Ms Gallagher would not confirm if Ms McCarthy or Ms McAllister would enter cabinet, but did hint the load could be shared more equally between the House of Representatives and the Senate.

With only four Labor senators in cabinet, the group have to answer for the rest of their colleagues' portfolios in question time and Senate estimates.

"Certainty the four Senate ministers that have been working hard would be looking forward to some extra support," she said.

"We have our processes to go through. They need to be finalised and the Prime Minister will be making the announcements he needs to tomorrow."