I'm surprised to see so many comments dwelling on the union issue.  This is about much more than that.  We all know that the Senate as it stands is all but useless.  The members almost to a man (and woman) enjoy a partisan sincecure based on years of toadying to whichever party appointed them.

Changing a bill passed by a duly elected government who more or less campaigned on it clearly demonstrates everything that is wrong with that house.  If we aren't careful with this one, we run the risk of degenerating into US style politics, where one house deadlocks the other.  We don't need a repeat of the woes suffered by them when the senate blocked an increase to the debt ceiling.

We should either eliminate this costly and wasteful exercise in non-democracy, or consider an elected senate.

And as an aside -- I believe unions are needed now more than at any time in the last 40 years.  Wage growth is flat, benefits are being cut, and CEOs are pocketing the majority of profit.