The Andrews government is preparing to unveil $8.3 billion worth of budget surpluses over the next four years, providing a hefty buffer to unleash new spending as next year's election looms.

Tuesday's state budget will confirm Victoria remains flush with cash, with strong revenues from property, business activity and rising employment flowing into Treasury's coffers.

Spending is expected to continue rising solidly, underpinned by a soaring public sector wage bill and other costs linked to booming population growth.

But that will still be slightly less than the growth in revenues, allowing the government to predict a $1.2 billion surplus for the coming financial year, rising to an annual average of $2.4 billion for the remaining three years of the budget period.