NSW politics faces uncertain times, with two likely leadership battles within the Coalition after shock resignations just days apart.

The Liberal party room will meet on Tuesday, facing a likely secret ballot to decide the next premier after Gladys Berejiklian’s abrupt departure on Friday.

Planning Minister Rob Stokes is pushing on with his bid to take the top job, despite a deal done to install his “good friend”, Treasurer Dominic Perrottet, after a weekend of behind-the-scenes factional wrangling.

“I believe I have got a lot to offer in terms of vision and integrity, and energy, and I’m committed to giving the party room a choice,” Mr Stokes said on Monday.

“Dominic Perrottet has a lot of great qualities [but] I believe in terms of experience, that I offer more. In terms of being able to speak to the people of NSW, there are a couple of challenging byelections ahead of us and I believe I am equipped and prepared for that challenge and for that journey.”

On Wednesday, the Nationals will meet to select their own new leader following Deputy Premier John Barilaro’s bombshell announcement on Monday that he would quit politics.

NSW Water Minister Melinda Pavey has confirmed she will run for the Nationals leadership. MPs Paul Toole and Adam Marshall are also considered contenders.

Mr Toole said he would deliberate on “how best I can serve our party” in the next 24 hours before announcing his final decision.

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Mr Barilaro’s resignation followed Ms Berejiklian’s shock announcement on Friday that she would step down after the state’s corruption watchdog disclosed she was under investigation for potential breaches of public trust given her secret five-year relationship with former MP Daryl Maguire.

She will formally step down as leader when the party elects her replacement, and will quit parliament altogether when a byelection for her seat can be arranged.

Also at the weekend, Transport Minister Andrew Constance announce he would quit state parliament before the end of the year to run in the federal seat of Gilmore – meaning a byelection in his seat of Bega.

NSW Labor leader Chris Minns accused Mr Constance and Mr Barilaro of putting their own ambitions ahead of the wider population.

“Regardless of the political turmoil, we do have an economic and health crisis in the state at the moment, and it is the responsibility of every member of parliament to put your community first and your own career second,” he said.

“There is the option of going to the backbench and serving your community, not on the front lines.”

Mr Perrottet has appealed to his Liberal colleagues to back him after striking a deal to make Jobs Minister Stuart Ayres his deputy and promote Environment Minister Matt Kean to treasurer.

He is a member of the Liberal Party’s right faction, while Mr Ayres and Mr Kean are from the dominant moderate faction.

Both he and Mr Stokes are fitness fanatics, fathers and men of faith.

But while Mr Stokes was elected to parliament as the Pittwater MP in 2007 during the Labor Iemma government’s tenure, Mr Perrottet – elected in 2011 – has spent no time in opposition.

Mr Perrottet has bounced around three electorates in as many terms – Castle Hill, Hawkesbury and Epping – but both have served as ministers in several portfolios since 2014.

Mr Stokes was minister for environment and education, while Mr Perrottet took on the finance and industrial relations portfolios before becoming treasurer.

Mr Perrottet on Monday played up his credentials working alongside Ms Berejiklian as deputy leader and argued for stability, saying he would bring unity to the party.

“As Gladys demonstrated so well, leading a successful Liberal and National government requires unity across our party’s ‘broad church’,” he wrote in an opinion piece published in The Daily Telegraph.

“We can only do that if we remain united, and maintain stability and continuity for the people of our state.”

Former prime minister and Liberal party elder John Howard has backed Mr Perrottet, saying he is driven and reform-focused.

-with AAP