Basically its just Bb, F, and Gm all the way through.
Picking pattern is quite interesting though, so listen to the track and try and work it out for yourself.
Bb              F             Gm         (Single note A on the bass string)
London, did you have to take my Child away
Bb               F          Gm     (A)
And bury him under rent and low pay
Bb               F          Gm            (A)
Ive been cycling around your empty streets
Bb               F          Gm          (A)
Ive been searching in the pouring rain

It continues like this throughout the entire song, but with beautiful violas and
accordions all played by dear patrick denny wolf(sighs).

Au Revoir