From the photo - that is not acceptable.
1) MK rate their double sockets as 19.5A *continuous*
Contractor defence:
- Dishwasher and w/machine will not be heating water continuously
Reality:
- It only takes 24hrs (IIRC) at 22.5A for severe discolouration & aging
- Appliance plugs are often not touched for years, so contact resistance & heating rises (MK test was just several hours, not minutes accumulated over years)
This is why smaller kitchens often use lots of 1G sockets in 1G+1G siamesed backboxes - each is ok for 13A, ie, kettle & toaster plugged into same.
2) The sockets could do with relocating &/or being IP rated.
There is a material risk of leakage from the plumbing.
The sockets are placed low down and in any case could be subject to spray.
IP box route:
- Eterna do simple IP65 enclosures to convert any BS1363 accessory
- Simply surface mount polycarbonate box, lid & 20mm gland entry
- Use Pratley 20mm glands with flat (FTE) cable
They are about £7-12 for 1G-2G and I am certain there is a 1G+1G siamesed box to take twin 1G socket outlets.
MK and others do IP rated sockets, but the double socket current limitation applies and the enclosures by their nature might increase heating.
3) Better solution is also Best Practice
- Unswitched socket outlet OR cord outlet behind the appliance
- 13A Switched Fused Connection Unit above the worktop
BR guidance:
- Built-in appliances require switching above
- Removeable appliances can have switching below
Personally I would not have any wiring accessory below a sink except in an IP rated enclosure. The same applies to any area where washing machine / dishwasher / tap flex hoses are involved. Those hoses are notorious for not being replaced when needed, only to spray profusely like a kitchen fitter when challenged sometime later.
... hmmm, someone knocking at my door with a router & worktop jig