Malcolm Turnbull and Bill Shorten have both told their MPs to focus on the Super Saturday by-elections and highlighted how to attack the other side.
In separate party room meetings in Canberra, the two leaders urged their MPs to stay disciplined and focus on winning the July 28 by-elections.
The opposition leader told his MPs there was nothing they could do about Labor's national conference being moved due to a clash with Super Saturday.
"Regardless of all of that, we need to focus on the by-elections," Mr Shorten said.
The party's national executive will on Friday officially endorse the recommendation the conference be held in Adelaide on December 16-18.
Having visited the four electorates in which Labor is running candidates, he said Labor's message was about health, schools, a big personal tax cut, and fighting against the coalition's corporate tax cut plans.
"The simple question was how many of your tax dollars do you want to give to the big four banks?" Mr Shorten said.
The prime minister, whose Liberal party will contest three of the five by-elections, told a coalition party room meeting MPs need to remind voters about the jobs they have created, and the coalition's strong border protection policies.
He said Labor's rank-and-file members disagree with Mr Shorten's border policies, and they will change them if they can.
Mr Turnbull said everywhere he went, voters responded positively to the government's decision to list new drugs on the Pharmaceutical Benefits Scheme, which the coalition could do because of the strong economy.
Various Labor factions have been gearing up for the conference as a key battleground over policies on refugees and industrial relations.
Four of the by-elections were called after three Labor MPs and an independent were found to be dual citizens while the Labor member in Perth, Tim Hammond, quit for family reasons.
The government said the Australian Electoral Commission recommended July 28 as the first available date after allowing time for candidates to complete new processes to prove their citizenship status and to avoid school holidays.
The by-elections are being held in the West Australian seats of Perth and Fremantle, Mayo in South Australia, Longman in Queensland and Braddon in Tasmania.
