Is this a Whitethroat? Any thoughts Please.

I have this bird marked down as a 'whitethroat' but never feel sure that it is correct ~ so I thought I might get some thoughts or a confirmation from you 'wise ones'.

I took it on the 29th May 2009. I was walking on the North Cornwall coastal path round Dodman Point, south of Gorran Haven. There was a big drop into the sea one side of me and a gorse hedge the other with fields behind, very windy and bleak.

This little bird was singing its heart out! All comments really appreciated,

David