Western Australia Labor's factional makeup has experienced a notable shift following the recent election results.

The party, previously benefiting from a strong left faction presence, faces a rebalancing after losing approximately six seats in the upper house, creating opportunities for the right-faction MPs known as Progressive Labor.

Labor's stronghold in the upper house allowed an influx of left-faction MPs, comprising about 40 of the party's 74 members.

With the election outcomes, the prospect of a new factional framework emerges, potentially positioning the left faction at around 33 seats and the Progressive Labor faction at 25 seats, alongside a small number of unaligned MPs.

Progressive Labor, which aligns closely with unions such as the Australian Workers Union, the CFMEU, and others, anticipates bolstering its numbers through the addition of new MPs in the upper house.

Anticipated newcomers include Andrew O'Donnell, linked to the shop worker union; UWA scientist Parwinder Kaur; assistant WA Labor secretary Lauren Cayoun; and government adviser Klasey Hirst.

The departure of Mark McGowan from politics left only three unaligned Labor MPs in the caucus, including Deputy Premier Rita Saffioti and Ministers Reece Whitby and Paul Papalia.

Reports indicate that Michelle Maynard, the new MP for Swan Hills, has shifted from the left faction to the unaligned category, further influencing factional dynamics.

Despite the rebalancing, Premier Roger Cook's upcoming cabinet is expected to maintain a dominant left faction presence.

The cabinet will see left faction representatives like Jessica Stojkovski, Meredith Hammat, and Matthew Swinbourn taking the places of retiring ministers Sue Ellery, John Quigley, and David Templman.

Water Minister Simone McGurk's position is uncertain, with potential cabinet replacement from fellow left faction MP Divina D'Anna if McGurk loses her seat.

The resultant cabinet structure is likely to result in ten spots for the left faction, four for the right faction, and three unaligned members.

Insiders suggest that the right faction may have to accept the current imbalance due to Cook's leadership and significant electoral win, reflecting a prior scenario under McGowan in 2021. Nevertheless, pressure may mount for adjustments in representation from the right faction, particularly regarding the influence of unaligned MPs like Whitby.

In terms of portfolio adjustments, expectations hint that the health portfolio might change hands from current minister Amber-Jade Sanderson, who seeks economic responsibilities, while Quigley’s former role as attorney-general is likely to transition to Education Minister Tony Buti.

The Labor caucus has plans to convene for the first time since the election, with initial meetings pushed back to the following Monday.