Mr Swan faces stiff competition from Labor, but if he manages to overtake its vote, he could slip in to the Senate on fewer than 5000 primary votes, with Labor preferences pushing him ahead of the conservative parties.

At the close of counting on Friday afternoon, the Sex Party was about 300 votes behind Labor, after preferences. The result would be an extraordinary outcome for Mr Swan, who splits his time between Canberra and Melbourne.

He said he would move to Tasmania ''in a flash'' if elected, and said one of his priorities would be to lobby for legal marijuana crops to be grown in Tasmania, alongside poppy fields.

''This could reverse Tasmania's economic woes,'' he said. ''It could become the marijuana capital of Australia.''

The would-be senator said his party was more than its name.

''The Sex Party, really, we're not about sex - in the same way the Liberal Party's not really about being liberal, and you could argue that the Labor Party's not much about organised labour these days,'' he said. ''So, the Sex Party's really about, you know, our five main policies are legalising and taxing marijuana, euthanasia, taxing the church, abortion as a national health policy and censorship.''

Mr Swan is co-founder of the Eros Foundation, a sex industry lobby group, with his partner Fiona Patten, who stood as Sex Party candidate in Victoria.

While some pundits have already excluded the Sex Party from their calculations of the Tasmanian Senate, an Electoral Commission spokesman said it was ''just too close to call''.

Most projections do not take below-the line votes into account, but in Tasmania about 10 per cent of voters voted below the line, compared with up to 3 per cent in the rest of the country.

''We don't make any predictions until we've finished counting, because it's just too close to call,'' the spokesman said.