Labor wants to see if the numbers stack up before supporting the government's plan to fast-track company tax cuts for small and medium-sized businesses.
Opposition Leader Bill Shorten said he would keep an open mind about Prime Minister Scott Morrison's plan to reduce the tax rate for companies with turnovers of less than $50 million to 25 per cent by 2021/22, five years earlier than first intended.
"We are not ruling it out and we are not ruling it in. We want to see the numbers. You just do not spend tens of billions of dollars on a whim," Mr Shorten told reporters in Brisbane.
Mr Morrison will outline the new policy - an update to a plan that originally envisioned corporate taxes being cut to 26 per cent by 2025-26 - in a speech in Melbourne on Thursday.
