Malcolm Turnbull has revealed his government is looking at how superannuation is taxed, saying it is "remarkably low".
But the prime minister confirmed the coalition will not be adopting Labor's plan to halve the 50 per cent capital gains tax discount for individuals.
On Monday he had emphatically ruled out increasing the tax, saying it was "no part of our thinking whatsoever".
But reports the next day suggested the government was considering halving the CGT discount for super funds, drawing Labor accusations of misleading parliament.
Mr Turnbull conceded the tax on the earnings of super funds in the accumulation phase was "remarkably low".
"What we are looking at is the entire superannuation system, as you would expect, in any responsible review of taxation, unlike the Labor Party, we are not rushing into snap decisions," he told parliament on Tuesday.
Mr Turnbull was quizzed on capital gains tax during question time by Opposition Leader Bill Shorten and shadow treasurer Chris Bowen.
"It shows the sad and childish desperation to which the opposition have sunk," the prime minister retorted.
Mr Bowen said Mr Turnbull's conflicting comments show he can't be trusted on tax.
"This is a government all at sea when it comes to tax but it goes to the very core not only of competence but of character," he earlier told reporters.
However, voters (48 per cent) believe Mr Turnbull is more capable of managing tax reform than Mr Shorten (26 per cent).
When it comes to handling the economy more broadly, the latest Newspoll found Mr Turnbull ahead of Mr Shorten 58-22 per cent.
Mr Turnbull was also ahead on education and health - traditional Labor strengths - as well as national security and asylum seekers.
Mr Shorten had the edge on industrial relations.
The Housing Industry Association backed the prime minister's decision not to change capital gains tax on housing, saying it was already taxed enough.
When it came to improving affordability, the focus should be on increasing housing supply.
"This won't happen by increasing taxes on housing," the association's Graham Wolfe said.
Mr Turnbull agreed, also telling a joint meeting of Liberal and Nationals MPs that Labor's plan to limit negative gearing to new properties would cause house prices to crash and damage the economy.
"Vote Labor and see your house price go down. That's what Labor is offering. Lower house prices, poorer Australians," he later told parliament.
