The Australian Sex Party has threatened Google with legal action after the search engine refused to run its ads on the eve of tomorrow's Melbourne by-election.

It comes after Sex Party ads were blocked by Google at the last federal election because the company - which is typically opposed to censorship - perceived the text as too racy (the ads were reinstated by Google the day before the election).

"We need to take this further. They are blatantly treating us differently to the Greens."

Sex Party candidate Fiona Patten said this time the search giant said it would not approve her ads "because we have a donate button on our page and we're not a charity".

"It's giving me the shits that in two elections we've not been able to run ads with Google when all of the other political parties have had no problem," she said.

Patten has accused Google of inconsistently applying its rules, as the Greens candidate in the state by-election, Cathy Oke, has ads running on Google despite having multiple donate buttons on her web page.

"We've sent them screenshots of the donate buttons on the ALP and the Greens sites and they've allowed all of those ads to run," she said.

The Greens could lose their bid for the seat of Melbourne because of a history of snubbing the Sex Party.

Preferences will be crucial in determining Saturday's by-election result, and the Sex Party will direct its preferences to Labor.

Sex Party candidate Fiona Patten said she was concerned by the "anti-sex feminist" element in the Greens.

A poll conducted this week by ReachTEL found that Ms Patten was attracting 6.1 per cent support, putting her in third place.

Greens candidate Cathy Oke was leading on 38.1 per cent, marginally ahead of Labor's Jennifer Kanis on 36.5 per cent.

This would mean the outcome would be decided by the preferences of those who vote for Ms Patten and other minor candidates.

This week's poll found that one in four voters would support a candidate other than Dr Oke or Ms Kanis.

More than 10,000 votes that went to the Liberals in Melbourne at the 2010 election are up for grabs after the party's decision not to stand.

Ms Patten said the stand-offish attitude from the Greens dates back to the 2010 election, and the influence of a moralist element in the party.

"We have been concerned about this Left-wing anti-sex feminist position," Ms Patten said.

For the information of Australian Sex Party Members

Please join us for a NSW Sex Party members meeting on:

Wednesday 1st August 2012
@ The Local Taphouse
Level 1, 122 Flinders St Darlinghurst (5 mins walk from Taylor Sq)
From 6:45pm.

This is a members only meeting. Please This e-mail address is being protected from spambots. You need JavaScript enabled to view it if you are able to join us.

We hope to see you there.

Voters in the Melbourne by-election have been found to be deeply divided about the Gillard government's performance and the Greens face a much tougher battle to secure the seat than the minor party has claimed.

Pollster ReachTEL has unearthed deep dissatisfaction with the Gillard government among many voters in the inner-city state seat, with more than a third of those surveyed revealing they were less likely to vote Labor at Saturday's by-election based on federal factors.

But the same number of voters declared they were more likely to stick with Labor on the back of Canberra's efforts, suggesting the rusted-on ALP vote may be holding up in the electorate.

The Brisbane-based pollster found that 70 per cent of voters would be influenced, negatively or positively, by the Gillard government's performance, despite the fact it is a state by-election.

This means that, regardless of the result, the fallout from the by-election will be felt nationally as well as in Victoria.

The ReachTEL findings come after The Australian revealed last week that internal Victorian Labor polling suggested three times as many people cited the performance of the federal government, rather than that of the state government, as the reason they would not vote for Labor.

The survey of more than 400 voters on Monday night reported the Greens candidate Cathy Oke securing 38.1 per cent of the first preference vote with Labor's Jennifer Kanis on 36.5 per cent, pointing to a knife-edge result that will be decided by preferences from the other 14 candidates.

Independents and other candidates do not appear to be polling strongly, with the Australian Sex Party's Fiona Patten the third-most popular candidate, securing just 6.1 per cent of the vote, followed by suburban councillor Stephen Mayne on 4.3 per cent. Family First's Ashley Fenn was lagging on 3.8 per cent. The Liberal Party is not running a candidate.