blue flowered bulb for ID

[gote]

For me they are to pale for Scilla siberica

Scilla siberica can be quite variable. Some variations are definitely as light as these.
That does not make sure they are siberica. Not being a Scilla expert I would have assumed them to be that if I had found them somewhere.
However, If I found them in Mark's garden I would assume something more exotic. 
Göte

[gote]

I dug up a picture of some lighte S siberica that I had put aside. These are self sown seedlings.
Göte

[ChrisB]

Mark, I've got Scilla reverchonii and that foliage looks a bit like the same as mine.  Here's my reverchonii

[tonyg]

Pretty sure it is Scilla reverchonii.  Looks like the plant I saw at Eric Jarretts under that name.  Makes a beefy clump, in a sunny spot in Gloucestershire it had impressive, dense flowered spikes of bloom.