Morton's Fork is an expression that describes a choice between two equally unpleasant alternatives (in other words, a dilemma), or two lines of reasoning that lead to the same unpleasant conclusion. It is analogous to the expressions "between the devil and the deep blue sea" or "between a rock and a hard place."
The expression originates from a policy of tax collection devised by John Morton, Lord Chancellor of England in 1487, under the rule of Henry VII. His approach was that if the subject lived in luxury and had clearly spent a lot of money on himself, he obviously had sufficient income to spare for the king. Alternatively, if the subject lived frugally, and showed no sign of being wealthy, he must have substantial savings and could therefore afford to give it to the king. These arguments were the two prongs of the fork and regardless of whether the subject was rich or poor, he didn't have a favourable choice.
Elected officers (MPs and councillors) sometimes may have recourse to a variant on Morton's Fork when dealing with uncooperative non-elected officers (civil servants). This variant asserts that a non-elected officer's non-compliance with the directive of their elected officer must be due to one of two equally unacceptable causes: either the civil servant is lazy or incompetent, or the civil servant is acting willfully or maliciously against the instructions given by his/her elected officer; this variant is the source of a great deal of humor in Yes Minister.
In the film Saw, the Jigsaw Killer forces victims to make a life or death Morton's Fork type decision. One example is the Venus Flytrap, in which a man is put into a death mask and is given a set amount of time to either cut through his eye and retrieve the key or die.
The film Mad Max has a similar situation where Max captures an enemy named Johnny the Boy and handcuffs his ankle to a wrecked, overturned vehicle with a ruptured petrol tank. Max lights a crude time-delay fuse and gives Johnny a hacksaw. He says "The chain in those handcuffs is high-tensile steel. It'll take you ten minutes to hack through it with this. Now if you're lucky, you can hack through your ankle in five minutes. Go." Soon after, an embittered Max drives off as the vehicle explodes behind him, leaving Johnny's fate unknown.