couldn't organise a piss-up in a brewery
Definition from Wiktionary, the free dictionary
Presents an example of a minimally simple project that the person or group described is presumed unable to accomplish.
- (Britain, Ireland, Australia, New Zealand, vulgar, slang, idiomatic) Is unable even to organise a project that requires no planning; is incompetent.
2006, G. C. Lemans, Chantier: A tribute to the world's engineers and their partners in life, page 60:
- “Deladrieux should have stayed an accountant,” Murphy sighed. “He's got three people working for him but they're just administrative clerks, pencil-pushers, they couldn't organise a piss-up in a brewery. That's what you get when you assign engineering jobs to non-engineers. […] ”