Is this a fungus or lichen please?

Is this a fungus or lichen please?

Observation - Is this a fungus or lichen please? - UK and Ireland. Description: Found on a stump within an area full of Fern/Bracken and heather. Hope someone can help as it was very attractive!

Found on a stump within an area full of Fern/Bracken and heather. Hope someone can help as it was very attractive!