Senior Labor figures concede that the party may not win the crucial marginal seats it needs to form the next government, despite two exit polls showing it ahead in percentage points.
A Channel Nine exit poll showed Labor taking 52 per cent against the Liberal/National coalition's 48 per cent.
A Sky News exit poll showed an even narrower marging of 51 per cent for Labor to 49 per cent for the right-wing coalition.
Tony Abbott's oppositon alliance need a uniform 2.3 per cent swing against Julia Gillard's Labor to win. The government, which has been in power for three years, has to win 76 of the lower house's 150 seats to stay in office.
The Channel Nine showed only a small swing towards the opposition.
But it also predicted a 5.1 per cent swing against Labor in vital marginal seats in Queensland and New South Wales.
"I would rather take the exit polls [in a positive] way but it is a fcat that we could have a narrow Labor victory, a narrow coalition victory or a hung parliament," former Labor Prime Minister Bob Hawke told Sky News.