Victorian Premier Ben Carroll to fill only one of three cabinet vacancies

The ABC understands Victorian Premier Ben Carroll will fill just one of the three vacancies in cabinet when caucus meets on Monday morning.

The meeting was planned to elect new ministers following former premier Jacinta Allan's resignation last week.

Last Tuesday, Ms Allan announced she would stand down ahead of an expected spill motion she was tipped to lose.

She had earlier written to Labor's state secretary vowing to contest any leadership ballot.

In a chaotic meeting, Ms Allan's ally Attorney-General Sonya Kilkenny also nominated for the leadership and threatened to drag the vote out for weeks.

She eventually made way for Mr Carroll's unanimous ascension to premier.

Transport Infrastructure Minister Gabrielle Williams was elected his deputy.

Mordialloc MP to be promoted

Two days after Ms Allan stood aside, ministers Harriet Shing and Lily D'Ambrosio also announced their resignations from cabinet.

Health minister Ms Shing was a close ally of Ms Allan and Ms D'Ambrosio was Australia's longest-serving energy and climate minister.

Their departure left three vacancies in cabinet for the new premier to fill.

But MPs have told the ABC that Mr Carroll had determined he would fill just one of the positions.

All three vacancies were in the Socialist Left, which had been left in tatters after last week's events.

Ms Allan's position had been guaranteed to Tim Richardson, who was expected to be elevated on Monday, in a deal brokered to resolve the leadership dispute last Tuesday.

The number of ministries is up to the premier of the day.

One MP said Mr Carroll was pitching this as an austerity decision. Another said with the election nearing, Mr Carroll did not want to be loaded up with novices in cabinet and that there are few remaining cabinet meetings before the November 28 election anyway.

At least seven MPs, all from the Socialist Left, had been jostling for the remaining two cabinet positions. Some of them were at risk of losing their seats at the election.

Josh Bull, Pauline Richards, Nina Taylor, Katie Hall, Ryan Batchelor, Sheena Watt and Sonja Terpstra were among the MPs seeking support.

Mr Richardson, the member for Mordialloc, was a government advisor before entering parliament more than a decade ago. He was recently promoted to cabinet secretary.

The Socialist Left had for years enjoyed dominance in Labor's factions — blocs within the Labor Party of MPs and powerbrokers aligned on policy and long-standing relationships. It was also home to former premier Daniel Andrews.

The Socialist Left was divided on whether to move against Ms Allan, in favour of Mr Carroll, who is from the Right faction. Two candidates from the Left had also nominated for deputy, which again divided the Left.