Yep, pipits, more specifically meadow pipits!
Many thanks! From where I was standing (in flood water) they were just little brown jobs. My camera got a closer view and then my Collins bird guide got me as far as suspecting pipitry.
@Ludd started
London Fixed Gear and Single-Speed is a community of fixed gear and single-speed cyclists.
Ludd
Yep, pipits, more specifically meadow pipits!