Mr Turnbull told the Weekend Australian newspaper his government was “absolutely committed” to delivering the tax cuts.
He said keeping corporate tax at an uncompetitive 30 per cent would cost jobs and see companies leaving the country.
Treasurer Scott Morrison wants Parliament to deal with the tax package before it rises at the end of this week for the last time before the May 9 budget. The proposal is for a 27.5 per cent tax rate for businesses with turnovers up to $10 million.
The government is struggling to get the tax cuts up in the face of opposition from Labor and the Greens, and only partial support from the Nick Xenephon team allowing only the 27.5 per cent rate for all companies with a turnover of up to $10 million now before parliament.
Opposition finance spokesman Jim Chalmers said the $50 billion plan was a “shambles.”
“I think it has dawned on Scott Morrison that if they don’t keep the tax cuts in the Budget, it would be hard for them to keep the Treasurer in his current role after the Budget,” Mr Chalmers told the ABC’s Insiders program.
“If they hang onto them, it will be up to Malcolm Turnbull and Scott Morrison to explain to the Australian people why they should wear cuts to family payments or a tax on Medicare at the same time as the Government gives $50 billion to the big banks and multinationals.”
Mr Chalmers also signalled that the Opposition will put pressure on the government to keep the deficit levy due to be removed on July 1.
Mr Chalmers said abolishing the deficit levy “will mean a tax cut for a millionaire of $16,400 a year or $315 a week.”
“If that deficit levy was necessary in 2014, when the deficit was only $11 billion, it’s more than necessary now that the deficit is $37 billion,” he said.