Treasurer Jim Chalmers has vowed to keep pursuing higher taxes on superannuation accounts worth more than $3 million, while playing down adopting new revenue measures, such as curbing negative gearing, to address yawning budget deficits.

Dr Chalmers, who on Wednesday will unveil the mid-year budget update confirming a return to deficit, said his focus was “unfinished business” on tax, including his thwarted plan to increase the tax on earnings generated on the portion of super accounts over $3 million.