throw a spanner into the works
Cause deliberate disruption
To throw a spanner into the works is to disrupt a plan or process by introducing an unexpected obstacle.
The image is of a wrench (spanner in British English) falling into machinery and jamming the gears.
American English prefers throw a wrench in the works or throw a monkey wrench: Everything was going smoothly until the permit delay threw a spanner into the works.
- fly in the ointmentSmall flaw spoiling everything
- throw a wrenchSabotage ongoing efforts
- obstructBlock or hinder passage
- interruptionBreak in continuity
- muddy the watersDeliberately confuse an issue
throw a monkey wrench · rock the boat · sabotage · interference · derail · undermine · hinder · wrench · foil · put the kibosh on · monkey wrench · hamper · delay · impede · thwart · upset the apple cart · failure · rain on someone's parade
throw a spanner into the worksfacilitate
Make something easier
grease the wheels · pave the way · enable · expedite · lend a hand
throw a spanner into the worksstay the course
Continue despite difficulties
steady the ship · fine-tune · troubleshoot · fix · repair
throws, thrown, throwing, thrower, spanner, spanners, workers, rework, overwork