Western Australia's premier is poised to embark on another cabinet reshuffle after asking Water Minister Dave Kelly to step down.
Mr Kelly, 60, joins fellow veteran Alannah MacTiernan in making way after being appointed as a minister when Labor swept to power in 2017.
It paves the way for Premier Mark McGowan to renew his cabinet before Christmas, with first-term MP Jackie Jarvis among those tipped for promotion.
Mr Kelly on Thursday said he accepted the premier's call.
"The premier has asked me to step down to allow for some renewal, and in particular to allow more women into cabinet," he told reporters.
"Since being elected in 2013, I've given my support to the leader, whether it be in opposition or in government.
"I've accepted every task that he's given me, and it's in that vein that I've agreed that I will stand down from cabinet."
Mr Kelly, who was also responsible for forestry and youth, has held the water portfolio throughout Labor's time in government.
He was dumped from fisheries in 2019 after having proposed a state intervention in the crayfish market, and lost the innovation and science portfolios last year.
Mr Kelly's resignation is likely to renew speculation about the future of Attorney-General John Quigley, who recently turned 74 and has served in parliament for two decades.
The premier has repeatedly backed Mr Quigley to continue in the role.
Asked whether he had been requested to resign on the basis of performance and whether others should follow, Mr Kelly said he was proud of his record.
"I'm not going to comment on other ministers," he said.
"I've had what's quite a rare opportunity, I've had it for six years ... I'm happy to accept the request that the premier's made today."
A veteran of WA Labor's Left faction, Mr Kelly had previously served as a union official.
He said his proudest achievements included securing funding for the LGBTQI community, and overhauling Water Corporation's hardship policies to stop customers from being cut off when unable to pay their bills.
In a statement, Mr McGowan said Mr Kelly had been an important part of his team.
"Dave's deep commitment to equality and fairness has guided his entire career, in the labour movement and in parliament," he said.
Mr Kelly said he intended to stand again in his safe Labor seat of Bassendean at the next election in 2025.