Can “on” be used as a preposition for “bargain”? (Please consider the examples below)

Question

1.) "The bargaining on/over employees' benefits should end now."

2.) "We can never bargain on/over our human rights."

Answer 1

"Bargain over" and "bargain on" have different meanings

bargain over
negotiate

the employees were bargaining over better benefits with management
the employees were negotiating better benefits

whereas

bargain on
count on / thought that

I never bargained on her coming back after she left.
I never counted on her coming back
I never thought she would come back