The idea is, of course, simplistic nonsense that clearly involved little thought since this notion is replete with problems, such as:
Who defines these 'values' and selects the 'British' subset - these sound like being essentially subjective statements so any force claimed for them would likely involve fallacious aruments (from authority, tradition, special pleading etc).
That they are subjective means they aren't fixed.
They can't be validated but can easily be invalidated by pointing out either any obvious flaws or fallacies or an absence of consensus whereby some refuse to be bound by them: for example if this involved pledging allegiance to the monarchy.
If, in true fudge style, anything contentious is avoided then this sounds to me like gesture politics of the worst kind.