If so, it would be a big blow to a Coalition government. Senator Sinodinos, a former senior Treasury economist, was long-time chief of staff to then prime minister John Howard, and is one of the most widely respected figures on either side. Serious political potential: Ms Hanson could reap a significant number of preferences from voters cast for other parties. Credit:Jacky Ghossein While he has been a senator for only two years, Opposition Leader Tony Abbott reportedly wants him to be finance minister if the Coalition wins. But as the most junior of the Coalition's NSW senators, he was given the vulnerable third place on its Senate ticket. The Coalition usually wins three seats with ease, but this time it looks uncertain. With few preferences going his way, the Coalition will need to lift its vote in an increasingly crowded Senate field - in which virtually all its traditional allies are directing preferences to Ms Hanson.

All forecasts of Senate outcomes are unreliable. In NSW, 110 candidates are standing for 44 parties or as independents. The order in which they are eliminated could decide who wins the final seat. But in 2010, 29 micro-parties won 14 per cent of the vote between them. This time there will be 41 of them, and disillusioned Labor supporters could swell their collective vote to 20 per cent - easily enough for a Senate quota. Their tickets are already locked in, and 99 per cent of voters are expected to follow them by voting ''1'' in the party box above the line. The Coalition, Labor, Greens and most left-of-centre groups put Ms Hanson last or almost last on their preferences. But most micro-parties are swapping preferences tightly with each other before giving any preferences to the big three. Ms Hanson could be the beneficiary. If name recognition gets her just 2 per cent of the vote, she will be one of the last ones standing, and could reap hundreds of thousands of preferences from votes cast for other parties.

But other micro-parties also have a chance of taking one of the final seats. They include the Liberal Democrats, who won first place on the Senate paper, the Sex Party, the Shooters and Fishers, and even the Stable Population Party. The Coalition and Labor are each certain to win at least two seats, with the Greens and Labor, despite their falling votes, likely to fight out the final seat The Reverend Fred Nile's Christian Democrats, a long-time Coalition ally, put Ms Hanson 12th on its preference ticket, Senator Sinodinos 37th. The Shooters and Fishers have Ms Hanson at 10, Senator Sinodinos 88. The DLP, Katter's Australian Party, Liberal Democrats, Sex Party and Family First are also preferencing the One Nation leader before the Coalition's rising star. Senator Sinodinos declined to comment to Fairfax Media on his chances.