Australia’s longest-serving energy minister, Lily D’Ambrosio, has called time on her career with the Victorian Labor party, advising her new boss, Ben Carroll, that she will not re-contest the seat of Mill Park at the election in November and will step down from the Cabinet.

The news emerged on Thursday afternoon, capping off what has been a tumultuous week for the party, with a change in leadership on Tuesday following the reluctant resignation of former premier Jacinta Allan.

D’Ambrosio, who announced her resignation alongside the state health minister Harriet Shing, has overseen one of Australia’s most ambitious and comprehensive state energy transition plans, including a legislated exit from gas in homes and plans to host the nation’s first offshore wind projects.

For Australia’s nascent offshore wind sector, the timing is not ideal, with D’Ambrosio due to launch the nation’s first ever – and already delayed – auction for offshore wind generation capacity in August.

But in a statement issued on Thursday afternoon, the minister said she was leaving the state well placed to continue on its decarbonisation journey.