M & S Per Una Blue Red WHite Floral Midi Shirt Dress Oversized 

Size10 but fits 12 14 16

Approximate measurements are as follows: 

Armpit to armpit - 21"

Shoulder to hem - 54"

Armpit to cuff - 

100% viscose

Excellent condition.  Please note that the dress is labelled size 10 but is very oversized and fits much bigger than this - please see above for approximate measurements.  Please see all photos.