It was on a thyme plant but it wasn't in flower. The yellow thing is a petal blown in from a neighbour's garden.
No interactions present.
This one is even hairier than the one I saw last year http://www.ispot.org.uk/node/257876 !
I'd like to submit a record of this observation and would appreciate confirmation (or otherwise) of this species ID: Osmia bicornis (male).
Lat/Lng: 52.061168, 1.159024
OS grid ref: TM166450
In my garden.