PRIVATE Labor Party polling shows the Gillard Government has suffered a swing against it of 5 per cent in parts of Victoria.
The leaked results of polling by UMR Research last month in the Labor-held seats of Bendigo and McEwen shows the ALP's primary vote has fallen 8 per cent since the 2010 election.
In two-party terms, it is down 5 per cent in Bendigo and 6 per cent in McEwen.
It would make both seats marginal in next year's election and force Labor to spend scarce resources to protect them.
And if the swing against the ALP was uniform, the knife-edge seats of Corangamite, Deakin and LaTrobe would fall to the Coalition.
It could also mean seats such as Chisholm, Bruce and Melbourne Ports would be in what one party figure called "the danger zone", although likely to be retained.
Sources said the two main issues of concern identified by voters in the polling were the carbon tax and Julia Gillard's leadership.
The polling does not include any response to last week's decision to drop the election promise to have a Budget surplus, which Treasurer Wayne Swan said had been done to protect jobs and growth but which ALP critics said raised questions about the integrity of Ms Gillard and Mr Swan.
"We're like a problem gambler just waiting and waiting and hoping something changes, and then trying to make a virtue out of looking silly," said one Labor critic.
If Labor were to lose seats in Ms Gillard's home state of Victoria, it would make its fight to retain power harder.
Other polling has suggested Labor faces losing seats in western Sydney and Tasmania. The ALP is hopeful it can pick up seats in Queensland, South Australia and Western Australia, but this strategy relies on holding seats in Victoria.
It also faces a problem if NSW independents Rob Oakeshott and Tony Windsor lose their seats.
Bendigo has been held since 1998 by Steve Gibbons, who will retire at the next election, while McEwen is one of just two seats Labor won from the Coalition in the 2010 election and is held by Rob Mitchell.
Victoria is Labor's strongest mainland state and in the 2010 election the statewide two-party-preferred vote was 55 per cent.
Opposition Leader Tony Abbott has been focusing on Corangamite and Deakin. He has visited Corangamite in southwest Victoria - the nation's most marginal seat - eight times since the Coalition fell short by 771 votes in the last election against Labor's Darren Cheeseman.
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