National advocate Kate Carnell has warned business owners will be crippled if they are forced to pay staff 0.5 percentage point more super from next July.

Ms Carnell has written to the treasurer proposing tax offsets she believes will ensure workers end up with a similar amount of retirement savings.

"We have to get the balance right by ensuring small businesses aren't hit with rising costs and workers are no worse off," she said on Friday.

Ms Carnell said the proposed tax cuts would cost no more than $6 billion per year.

"Ultimately, by implementing this proposal, the federal government would be supporting small businesses and all Australians who deserve a dignified retirement."

Australian Associated Press