A Labour leader taking many shares out (6)
I believe the answer is:
allots
'shares out' is the definition.
('allot' can be a synonym of 'share out')
'a labour leader taking many' is the wordplay.
'labour leader' becomes 'l' (the leading letter of 'labour').
'taking' means one lot of letters go next to another.
'many' becomes 'lots' (lots of something).
'a'+'l'+'lots'='ALLOTS'
(Other definitions for allots that I've seen before include "Allows to have" , "Distributes, gives as share" , "Apportions or assigns" , "Dispenses or distributes" , "Gives, apportions" .)