I have seen these before wandering around at night but I fished this out of the drain this morning. It had fell through the grate and was trying to stay afloat.
It could be a Lesser Stag Beetle,
looks quite like one,
I think its one of the ground beetles, poss pterostichus madidus.
The stag don't seem to have the antenni according to the book.
If it is its a common beetle.
Wait for others
having googled both the lesser stag is chunkier and black my beetle is more like one of the ground beetles. Having looked at my pic again I realised that the violet tinge to it isn't showing very well.
dug out a couple of other pics i took so you can see the colour i mentioned although in the pic it doesn't look as violet!!!! :/ more like a browny red!!
looks more like the violet ground beetle now
I think you've cracked it Ray
I would say looking at the link that it is probably that. I started seeing them in March at night as per description on the site. Thanks all :)