He added: "We must now admit that our previous concepts of public property have proved untenable."

If any deduction from it should prove untenable, it must be given up.

The cooperative ownership structure also proved untenable, because banks wouldn't give prospective families mortgages.

This attractive theory was too often proved untenable by the harsh realities.

This is not the time to stick at principles - at least ones which have proved untenable.

But he prepared himself to cast aside any assumptions that proved untenable, as many would in the inevitable course of things.

It will in the long run prove untenable.

The pace proved untenable, and not just for him.

How ironic should both forms of government prove untenable as we approach the 21st century.

For ministers to ignore Parliament completely would prove equally untenable.