Pre-election simulations had suggested the Coalition was likely to fall well short of a Senate majority. The swing to the Coalition in early counting was clearly too weak to change that prediction, with the Palmer United Party claiming much of a stronger swing against Labor. The new party appeared strongly placed in early counting to snare Senate seats in Queensland, with a double-digit primary vote, and more surprisingly in Tasmania.

The strength of the swing to the Coalition in Tasmania also increases the government's chances of snaring a third Senate seat, to Labor's two, with the Greens facing the Palmer insurgency for the sixth Senate spot.

Anxiety was high for the Coalition in NSW, where Arthur Sinodinos, who could be a senior figure in the new government, was in a life-and-death struggle with One Nation's Pauline Hanson for the state's sixth seat. Despite a primary vote of only 1.25 per cent, a very strong preference flow appeared likely to get Ms Hanson across the line, although three-quarters of the vote remained to be counted last night.

Across the nation, only about a dozen Senate seats are in play, with half of these likely to be determined by a labyrinthine flow of preferences among a record number of minor party candidates.

On pre-election polling figures, simulations had shown the Greens could win six Senate seats, taking their total to 12, but the early counting was discouraging for the party, which suffered swings against it.