The Albanese government has increased net spending by more than $24 billion over the next four years, including $300 in power bill discounts for every household and $325 for small businesses, in a move which Treasury says will cut inflation by 0.5 percentage points next financial year.

In a budget that raises the spectre of an early election, Treasurer Jim Chalmers relied on a late tax revenue surge to forecast a $9.3 billion surplus for this financial year, up from the $1.1 billion deficit forecast in December, before embarking on a spending spree that drives the budget headlong into deficit for the next decade.