Will Britain Obey the Geneva Convention?

In Britain:

Patients at Rampton high security psychiatric hospital, which houses some of the country's most dangerous criminals, are challenging a smoking ban in a test case which claims the refusal to permit cigarettes in the hospital's buildings or grounds violates their human rights.

This is, of course, in accordance with the Geneva Convention:

Sufficient drinking water shall be supplied to prisoners of war. The use of tobacco shall be permitted.