Billionaire businessman Clive Palmer leads the LNP's Ted O'Brien by just three votes in the Sunshine Coast seat of Fairfax.

A recount of preferences is underway after an initial count put Mr Palmer 36 votes ahead of Mr O'Brien.

Yesterday morning Mr Palmer was 42 votes ahead, but by last night the mining magnate's lead had narrowed to three votes.

As the painstaking count continues, tensions are rising.

Last week the Australian Electoral Commission flew in its chief legal officer to deal with an unusually high number of challenges on the validity of ballot papers.

The Palmer United Party, which may also hold the balance of power in the Senate, has four lawyers and the LNP has one.

Palmer's scrutineers are being delivered gourmet lunches from the billionaire's luxury Coolum resort, while Mr O'Brien's team gets the rare sandwich or roll.

Mr Palmer last week repeated his claim that there was evidence of voter fraud in the electorate, raising questions about why the AEC does not require voters to supply identification and why pencils are used to mark the ballots.

Returning officer David McKenzie says it is exhausting work.

"I'm tired," he said yesterday morning.

"It's been a long election and since election day it's been a very solid bit of work we've been putting in."

The commission cannot say when counting will end.

Senate results to be declared today

Meanwhile, the AEC will declare the Senate results for Victoria, South Australia and the ACT later today.

The Victorian and ACT results will be declared this morning while South Australia's Senate candidates will be confirmed after lunch.

Western Australia's results will be declared on Wednesday afternoon.

Greens Senator Scott Ludlum is in danger of losing his seat.

He is in a tight contest with Labor's Louise Pratt, but both the Australian Sports Party and the Palmer United Party also have a chance of winning the seat.

The WA result is so close that there will almost certainly be a recount.

There has been no date or time set for the declaration of the New South Wales and Queensland Senate results.

The results for Tasmania and the Northern Territory have already been declared.