The Nationals' Coalition partner, the Liberals, last week announced it would direct preferences for Pauline Hanson's party below Labor.

Mr Martin said the Nationals had traditionally avoided determining preferences until nominations had closed.

"The comments made by One Nation and the actions of One Nation are deplorable and disgusting, but as the Nationals have done for the past 100 years at every election, once all candidates are known, the nominations have closed, we will then be making decisions on preferences," he said.

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Mr Martin also said it would "be up to Tasmanian voters" to determine where they placed One Nation.

One Nation leader Pauline Hanson encountered criticism from Premier Will Hodgman and Port Arthur massacre responders after she was secretly filmed appearing to question the massacre.

Party officials were caught attempted to secure $20 million in foreign funding from the National Rifle Association in exchange for weakening Australia's gun laws.

In a press conference, Ms Hanson described party official Steve Dickson as a "victim of entrapment" and claimed she did not have doubts about the Port Arthur massacre.

In a media interview, Ms Hanson said she had read a "blue book" about the massacre but could not recall the title or author. She previously had to distance herself from Port Arthur conspiracy theories in 2001.