Need help identifying this bird call

I've got these recordings of a bird call I didn't recognise. It was in a churchyard in Durham. It repeated the same phrase over and over for ages.

I've gone through lists of UK bird calls but I can't find one that matches the distinctive pattern, if anyone recognises it I'd appreciate having the answer to my curiosity! 

(I hope the MP3 file uploads okay - there is some background noise but if you turn the volume up it should be pretty clear, at least it is on my phone)

5483.Unknown bird2.m4a