Looking at the flying gear of the chap on the left the photo is from 1940-1941, B type flying helmet, early mae west...
The description suggests these are pilots from a army co-op squadron and from memory poles had one co-op sqd and that was 309 Squadron.
Try going through these websites for extra images: polishsquadronsremembered.com or polishairforce.pl these are the best sites on PAF history and photos.
Good evening Cichociemny,
Thanks very much for the websites. Yes, that was my opinion about the year when the photograph was taken.
Actually, I found the Flight Lieutenant's identity ( far right ) on POLISH SQUADRONS REMEMBERED. It is Maciej Piotrowski.
To be continued...