Australian Prime Minister Kevin Rudd is on the brink of defeat in next month's national elections, with a poll indicating that his ruling Labor Party will lose seven of the eight most marginal electorates.

An analysis of the seats, four of which are held by Labor and the others by the opposition coalition, show Rudd's party would only win one if the election were held now, according to a JWS Research poll in the Australian Financial Review on Saturday.

Adding three seats would almost be enough to make Tony Abbott, leader of the Liberal-National coalition, prime minister, it said.