In an small office environment, is there a requirement for the incoming electrical mains to to encased to offer 30 mins FR? In this example the incoming cable is housed in a wooden cupboard along with the consumer unit ( a new metal case type.)

Where is it in regard to escape routes, exits, etc?

There's a fire exit front and rear, the electrical cupboard (with no FR)  is adjacent to the rear fire exit. There are sprinklers and SDs and MCPs.

If the consumer unit itself is to the latest standard and thus a 'non combustible housing' there's an argument it's tolerable as it is.

Don’t forget that the latest standard you refer to AB is for domestic and similar installations. Irrespective of any regulatory imperative, it may be prudent to have the equipment enclosed in appropriately rated construction, if not for life safety then for property protection/ business continuity. 
I speak from bitter experience for as a young electrical contractor just starting to make a future, I razed to the ground a fair part of a National Trust facility. As it turned out, there was a component failure where a poorly constructed fuse carrier in a heavily loaded switchfuse caused the connection to overheat. The cable insulation  burned back and molten parts fell on combustible material that had gathered around the bottom of the equipment. The place was undergoing refurbishment at the time and there was a big push to open. A fully fire resisting enclosure was in place but the builder hadn’t fitted the doors to it and staff had piled cardboard boxes smack up against it. 
The investigation team acknowledged that it was component failure but it didn’t do my reputation any good at all! What it did do though, was to give me an abiding interest in fire safety and that has been with me for forty years!

Incoming electrical cables and fuses should be encased in a protective covering, such as conduit, to protect them from damage and to ensure the safety of people and property. This is a common building code requirement and is also recommended by the National Electrical Code (NEC).