pushing water uphill
a descriptive phrase for attempting any hopeless task. If you've ever tried to push water uphill you'll understand the concept.
literal-Part of my job involves clearing water from the floor of my work station. Because the floor is pitched away from the drain, it takes an inordinate amount of time to clear the water, because I'm always pushing it uphill.
figurative-Asking your boss for a raise in these times of tight money makes as much sense as pushing water uphill.
figurative-Asking your boss for a raise in these times of tight money makes as much sense as pushing water uphill.