Opposition Leader Tony Abbott has avoided questions about National Party frontbencher Barnaby Joyce's decision to preference One Nation.

Mr Joyce is the favourite to win the seat of New England in northern New South Wales, but his decision to put One Nation ahead of Labor and the Greens on his how-to-vote cards has infuriated some people in the electorate.

Asked about it this morning, Mr Joyce said it was time to forgive and forget the right-wing party's past.

Mr Joyce says the party's members are not bad people, although he does not agree with their policies.

"They've been tarred with a brush that I think should be removed now," he said.

"You've got to know how to forgive, forget and move on, and I'm hoping that's what we do. You've got to show a sign of it in how you act yourself."

Abbott says issue 'a blast from the past'

But Mr Abbott, who has in the past called groups such as One Nation "racist", avoided commenting on the preferencing decision.

"I think really that particular issue is a blast from the past," he said when asked if it was the right move.

"The essential thing is to ensure that fringe parties do not get an undue influence in our national life.

"That's why I am determined to preference the Greens behind Labor and I am incredibly disappointed that Mr Rudd has lacked the courage, the strength and the decency to do likewise.

"The current problem is the Greens and that is why the Greens should be put behind the Labor parties."

Labor says decision shows 'appalling lack of judgment'

Labor's campaign spokeswoman Penny Wong has told ABC News 24 the decision is offensive.

"This is the bloke who wants to be deputy prime minister if Tony Abbott wins, saying that we should overlook the prejudice and racism that One Nation regrettably brought to Australia," she said.

"I think it shows appalling lack of judgment, an appalling lack of sensitivity and respect to the very many multicultural communities in Australia to whom One Nation was so disrespectful."

One Nation co-founder suing Tony Abbott

Mr Abbott remains embroiled in legal action over a trust fund he set up in 1998 to help bankroll civil court cases against the One Nation party and its founders.

David Ettridge and fellow co-founder Pauline Hanson served 11 weeks of a three-year jail sentence after being convicted of electoral fraud in 2003, although the conviction against Ms Hanson was ultimately overturned.

This year Mr Ettridge served Mr Abbott with legal papers, alleging he unlawfully assisted and encouraged the litigation against One Nation.

In May, Brisbane's Supreme Court told Mr Ettridge to resubmit his claim, saying the initial documents had been filed in the wrong format.