Labor accused the government of deliberately choosing July 28 for the Super Saturday by-elections to disrupt the party's conference on the same weekend.
The party's national executive will on Friday officially endorse the recommendation the conference be held in Adelaide on December 16-18.
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.
