Treasurer Jim Chalmers has told voters they will have to ride out another 18 months of spiking inflation eating into their take-home pay, as business calls on unions to walk away from excessive wage claims.

Labor went to the election promising real wage growth and, in a much anticipated economic update to parliament on Thursday, Dr Chalmers revealed headline inflation would peak at close to 8 per cent and wages would need to grow at the fastest pace in a decade to catch up by 2024.