Experts say One Nation preferences could have a deciding impact on the outcome of a crucial by-election this weekend.

The dual citizenship fiasco is forcing voters back to the polls in five seats across the country and it appears federal Labor might be in trouble.

A poll shows Labor risks losing the crucial Queensland seat of Longman after One Nation decided to preference the Coalition.

But Pauline Hanson appears to be missing in action and has denied plans to pull her Longman candidate from the race.

Senator Hanson was overseas in Scotland just last week, spotted by Ben Fordham’s father at a chemist.

One half of The Big Guns Andrew Bolt is questioning her “odd” absence, asking Graham ‘Richo’ Richardson whether he’s seen this before.

Andrew: “I just want to know from Graham… when was the last time you saw a leader of a reasonably big party disappear from the campaign trail in the last week?”

Graham: “I don’t think I’ve ever seen it. I can’t recall ever seeing it.”

Richo says it’s particularly strange considering the party has her name on it.

“How can the person whose party it is, who actually owns the party lock, stock and barrel… be overseas for two weeks?

“The last two weeks of the campaign as important as this? It is bizarre.”

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When it comes to whether Labor will see a major swing against them this weekend, Richo is careful to make a call.

“I can understand why Bill and why Malcolm Turnbull both claim to be underdogs but as far as I’m concerned it’s pretty much 50/50.

“I’m not going to make any bold predictions, I really don’t know.”