(alsolike rats deserting a sinking ship,like rats from a sinking ship)used to refer topeopleleavingaplace,organization,activity, etc. veryquicklyand inlargenumbers, because it isfailingin some way:
Formerfriendshavedesertedthecouplelikeratsleavingasinkingship.
Hisaidescouldfinallydepartforlucrativeprivatesectorjobswithoutlookinglikeratsdesertingasinkingship.