More information required.
What was the habitat? Where there any trees nearby? Where in the UK did you find them?
OK...I sent the pictures to Leif Goodwin, who is a nature/fungus photographer. He suggested Phaeolepiota aurea, and I think he's probably right. Common name is "Golden Bootleg", and it is indeed rare. This is the sort of mushroom that field mycologists get very excited about. It does occur outside the Highlands, but I've never seen one.
Well if he want me to post him one?
You can send a dried specimen to Kew if you want to get it recorded, but I suspect Leif would prefer you left them where they are to do what they are supposed to do!