Historically the Labor Party & its working class supporters have been anti-immigration on the assumption that immigration supressed working class wages.
Up to the Fraser Government, there was a racial component to anti-immigration. Bob Hawke, while head of the ACTU in the late 60s & 70s was vehemently anti-immigration. Ironically Fraser was pro immigration.
There are economic, racial & cultural objections to immigration but most on this thread do not qualify which is the basis of their objection.
Covid has highlighted our dependance on Backpackers which is a form of temporary immigration.