I agree, Mr XH588 - this is the nearest equivalent on the Highway Code website (the image seems to have a huge transparent border round it, in case anyone's wondering why there's so much blank space here...)

According to the description, it's a 'Controlled parking zone': "Some areas are designated as controlled parking zones. The entry sign indicates the times when waiting is prohibited."
The sign above is a "repeater sign indicating the times when waiting by goods vehicles over the maximum gross weight shown is prohibited".
So Wanna's sign means buses and cars with a caravan are prohibited during the hours specified.
I'd guess it's simply to stop caravanners using the area as an overnight site, and to stop buses parking there all night

And the sign above in this post is probably for a similar purpose - to prevent truckers using the area as an overnight stop, or to stop them parking there all weekend maybe because they can only do what they need to do Monday to Friday.