The senator who defended the rights of smokers and said they were being disproportionately slugged through tobacco taxes has confirmed his party accepted donations from tobacco giant Phillip Morris.

Liberal Democrat senator David Leyonhjelm confirmed the donation to Fairfax Media and said while he could not recall the exact amount given to his party by the tobacco company, it was in the "tens of thousands".

And in a provocative comment, said the donations had influenced his stance on plain packaging.

"I've gone from being strongly opposed to totally opposed to plain packaging," he said.