put/throw a spanner in the works

British & Australian, American

to do something that prevents a plan or activity from succeeding.

We were hoping to get the project started in June but the funding was withdrawn so that rather threw a spanner in the works.

The sudden withdrawal of the guest speaker really threw a monkey wrench in the works.

• the goggle-box
• the good old days
• the gory details
• the gospel truth
• the grand old man of
• the grand old man of something
• the grass is always greener .
• the grass is always greener on the other side of the fence.
• the grass roots
• the graveyard shift
• the gravy train
• the greasy pole
• the great and the good
• the greatest thing since sliced bread
• the green-eyed monster
• the Grim Reaper
• the groves of academe
• the hair of the dog
• the hair of the dog that bit you
• the halcyon days
• the hand that rocks the cradle .
• the hand that rocks the cradle rules the world.
• the happy event
• the hard sell
• the hard stuff