To walk the plank

to walk along a plank laid across the bulwark of a ship, until one overbalances it and falls into the sea; - a method of disposing of captives practiced by pirates.
to walk off the plank into the water and be drowned; - an expression derived from the practice of pirates who extended a plank from the side of a ship, and compelled those whom they would drown to walk off into the water; figuratively, to vacate an office by compulsion.
- Bartlett.

See also: Plank, Walk

References in classic literature ?
At present, in the splendid autumn weather - the autumn at least was a pure boon in the terrible place - he loafed about his "work" undeterred, secretly agitated; not in the least "minding" that the whole proposition, as they said, was vulgar and sordid, and ready to climb ladders, to walk the plank, to handle materials and look wise about them, to ask questions, in fine, and challenge explanations and really "go into" figures.
A portion of several boards holding together had fallen across the rail, and one end protruded overboard, like a gangway leading upon nothing, like a gangway leading over the deep sea, leading to death--as if inviting us to walk the plank at once and be done with our ridiculous troubles.
But once, the mood was on him too deep for common regardings; and as with heavy, lumber-like pace he was measuring the ship from taffrail to mainmast, Stubb, the odd second mate, came up from below, and with a certain unassured, deprecating humorousness, hinted that if Captain Ahab was pleased to walk the planks, then, no one could say nay; but there might be some way of muffling the noise; hinting something indistinctly and hesitatingly about a globe of tow, and the insertion into it, of the ivory heel.
Carol was the first to walk the plank, but before she could reach the end it started to wobble.
It is time for the Tanaiste to wake up to the imploding crisis before he is forced to walk the plank too.
Prepare to walk the plank into what will be a fun-filled day full of action packed activities for the whole family.
Slightly more popular (12%) was the suggestion that known pirates should be forced to walk the plank.
BALANCING ACT A seal being taught to walk the plank during feeding time at Tynemouth's Blue Reef Aquarium
Chelsea plundered two Premier League titles with the Special One at the helm but he was made to walk the plank in 2007 after falling out with owner Roman Abramovich.
I am not a betting man but if I was I would expect Mr Brown's erstwhile protagonist of the Blair days to be required to walk the plank within a short while.
If he didn't, then more reason that it should be he to walk the plank, along with his first mate.
AN ANGRY dad told council chiefs to walk the plank yesterday after they banned him from flying the Jolly Roger at his son's pirate party.