Higher-than-expected inflation will take at least 12 months to fall anywhere near the Reserve Bank of Australia’s target, casting doubt on Treasurer Jim Chalmers’ more optimistic forecast and making interest rate relief difficult before the next federal election.

The median forecaster of 38 economists polled for The Australian Financial Review’s quarterly survey does not expect underlying inflation to return to within the 2 per cent to 3 per cent range until next June.