I'm about to lose an existing double-gang wall socket behind a new wardrobe,
and would like to run a plugged-in extension lead from it to a new
surface-mounted socket just beside the wardrobe.

What little exposed flex there will be between the edge of the wardrobe and
the new surface box can be trunked in, so I'm not concerned about exposing
it to potential damage.

I've been trying to find out if there's a surface-mount box (single-gang
would do) with less protrusion than the usual 25mm (purely because it would
look less clunky).

And also if it's possible to get a conventional-type three-pin plug with
less depth than the standard (since there's not going to be much clearance
behind the wardrobe).

I've looked in the obvious places but without luck; I wonder if I'm using
the wrong search terms. Any pointers in the right direction would be very
welcome. Thanks.