Helping Britain in standing (7)
I believe the answer is:
abiding
'standing' is the definition.
('abide' can be a synonym of 'stand')
'helping britain in' is the wordplay.
'helping' becomes 'aiding' ('aid' can be a synonym of 'help'**).
'britain' becomes 'b' (common abbreviation as in GB).
'in' indicates putting letters inside.
'aiding' placed around 'b' is 'ABIDING'.
(Other definitions for abiding that I've seen before include "firm" , "With a lasting quality" , "Durable, lasting" , "Unceasing or putting up with" , "Enduring - constant" .)