Short on funds, the project is hard to keep going.
Tips
history
Derived from 《礼记·檀弓上》: Confucius remarked 哀则哀矣，而难为继也 - the mourning is sorrowful enough, but hard to keep up. The original sense of something genuine but unsustainable.
usage
Formal/written register. Used of business models, policies, lifestyles, relationships - anything whose continuation is in doubt. Subject usually precedes, not follows.
