He said that no government had won a by-election since 1920.

“History says Labor should win in Braddon but in Longman in Queensland One Nation preferences will come into play,” Dr Bonham said.

“Braddon is very marginal on 2.2 per cent so that means it is close enough to be loseable.”

Dr Bonham said the outcome of the Braddon by-election would come down to the campaigns run by the major parties.

“The historic factor makes it easier for Labor and it will depend on how hard the Liberals go, or whether they want to keep their resources for the general election,” he said.

“Labor does better in the urban centres while the Liberals do better in the rural areas.

“I expect there will be the usual pork-barreling.”

Dr Bonham said it was difficult to determine if the Liberal Party’s recent win in the Tasmanian election would flow through to Braddon.

“It is too hard to suggest that it will help, I wouldn’t rely on it.”