Finance Minister Mathias Cormann is insisting on the need to legislate tax cuts for big companies despite a warning from former prime minister Tony Abbott that there are "no votes" for the policy after the Coalition defeat in crucial byelections on Saturday.

In a strong defence of the economic plan, Senator Cormann said he intended to put the company tax cuts to the Senate and said the government’s position was to take the policy to the next election even if the Senate blocked the changes.

Fairfax Media has spoken to ministers and backbenchers who have expressed concerns about the policy, setting up a debate in coming weeks about whether to amend or drop the cuts before the next election.

Mr Abbott told radio station 2GB the government needed to change policies but not leaders in response to the byelection outcomes, fuelling the discussion about how Prime Minister Malcolm Turnbull should act on the message from voters.

"I don’t want to change the leader, I want to change the policy. If you change the leader without the policy you’re jumping out of the frying pan into the fire," Mr Abbott said.