By business reporter Daniel Ziffer

An extremely embarrassing day for some Australian businesses — and an enraging moment for many workers — is coming.

Early next year, the gender pay gap — the difference between what men and women are paid in the same organisation — of every company with more than 100 employees will be published.

Expect fireworks.

“I’ll probably pop some champagne,” laughs columnist and women’s advocate Kristine Ziwica. “This is a massive, massive shift and something that I have been waiting a very, very long time for.”