The forecast budget surplus should be sacrificed to support consumers, according to Westpac's chief economist Bill Evans, who argues that the federal government should provide more help to the Reserve Bank ahead of what traders see as a 50-50 chance of a historic rate cut next month.

"I want them to bring forward the stage two tax cuts," Mr Evans said. "If it turns out that's at the expense of the surplus, then that's the price that needs to be paid given the state of the economy at the moment."