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.

ReachTEL asked Liberal voters from the 2010 state election for whom they would vote. Of these, 25 per cent backed Mr Mayne - a Kennett government spokesman - and 17 per cent opted for Family First.

Ms Oke would secure 10 per cent of the former Liberal vote and Labor's candidate 15 per cent.

The preference flows to Labor and the Greens appear to be roughly divided, suggesting a tight result.

In the 2010 general election, Labor polled 36 per cent of first preferences, the Greens' 32 per cent and the Liberal Party 28 per cent. There were nearly 44,000 voters.

The poll suggests the Greens have a tougher task than some members have suggested.

Voters were asked whether they supported the $5 billion-plus East West Road Tunnel project - 28.3 per cent did, 50 per cent were opposed and 22 per cent were undecided.

The controversial project would link Melbourne's east and west by a long tunnel and road system in and near the by-election seat. Both the Greens and Labor oppose the tunnel.

Victorian Premier Ted Baillieu yesterday said Labor was odds-on to win Melbourne.

"They've held it for 100 years, that would be my expectation," Mr Baillieu said.

Source: The Australian