unsustainable

"There is a real risk our debt becomes unsustainable this Parliament, unless we make tough choices about what the state does. We can't keep on muddling through."

Musk's noisy opposition has rested, in part, on his warning that the growing US debt is becoming unsustainable.

Scotland's largest teachers' union has described the workload in schools as "unfair, unhealthy and unsustainable".

For several years, the top tennis players have said the physical demands on them are becoming increasingly unsustainable.

The fashion is impractical, the lifestyles unsustainable, and the New York dating scene is . . . depicted realistically, from what I'm told.