Mortice Nightlatches

If I am correct in thinking that there is no such thing as a mortise nightlatch then the answer is that Been and Queued don't sell them. My understanding is that only rim/cylinder locks can have a nightlatch. Do you mean a mortise deadlock?

Does it need to be on the rim to be a nightlatch? This seems to meet the essential criteria:

Surprisingly B&Q stock a very good range of locks. That is wood type locks, "not plastic door locks sir, we don't do those", when I just wanted a simple euro lock barrel. :(((

Arses!

I agree they have a good range of the vanilla stuff, sashlocks, deadlock, rimlocks, latches and windowlocks but boy is it at a price, they're so expensive even my local locksmith can beat them. Thought the latches were a bit 'interior' grade, nothing really suitable as a morticed nightlatch replacement.