Mushroom identification

Strange mushroom: stem and gills

Can anyone help me identify this mushroom?

Strange mushroom: cap and stem

It appeared under my lawnmower yesterday as I was mowing the edge of the lawn. It might have been growing in the lawn or under the heather beside the lawn – I don’t know which as it appeared already uprooted. It has a very blue cap and pale pink gills.

Cap of mushroom, with hand for scale

(Don’t worry, I’m not eating it, whatever anyone says!)