1
general::
Phrase(s): the last straw [and] the straw that broke the camel’s back
the final difficulty in a series; the last little burden or problem that causes everything to collapse. (From the image of a camel being loaded down with much weight. Finally, at some point, one more straw will be too much and the camel’s back will break.) • When our best player came down sick, that was the straw that broke the camel’s back. We hoped to make the playoffs, but lost all the rest of our games. • When she showed up late a third time, that was the straw that broke the camel’s back. We had to fire her.
McGrawhill's American Idioms And Phrasal Verbs