Unionizes vs Unionises - What's the difference?

As verbs the difference between unionizes and unionises

is that unionizes is third-person singular of unionize while unionises is third-person singular of unionise.

(head)

(unionize)

(unioniz)

(ambitransitive) To organize workers into a union.

The company laid off all the workers when they tried to unionize .

My uncle got roughed up by some corporate thugs after they caught him trying to unionize their workers.