Eight years working at the checkout of a suburban Kmart can instil many things in a young man’s character.

Humility. Resolve. An ability to navigate conflict and wear criticism.

But perhaps endurance is the trait Ben Carroll developed behind the register that has served him best during his 14-year parliamentary career.

On Tuesday, that career could reach its pinnacle: a looming spill motion at a morning meeting of MPs may unseat Jacinta Allan and install Carroll as the 50th premier of Victoria.