ACTU secretary Dave Oliver says the union movement is prepared to work constructively with a coalition government.
But he says he doesn't expect to receive a courteous reception if Opposition Leader Tony Abbott wins the September 14 election.
Mr Oliver said the union movement "didn't walk away" from negotiating with the government on industrial reform when John Howard defeated Labor in 1996.
"The union movement is prepared to work constructively with any government," he told the National Press Club in Canberra on Wednesday.
However once the coalition came to power in 1996 "the doors were slammed in our face".
Mr Oliver said Howard government ministers "didn't have the courtesy to write back" in relation to union enquires about policy.
The question of collaboration with the industrial movement was one for Mr Abbott, he said.