Is a Liberal permitted to barge in here? (5)
I believe the answer is:
canal
'barge in here?' is the definition.
(a barge might travel through a canal)
'is a liberal permitted' is the wordplay.
I cannot quite understand how this works, but
'a' could be 'an' and 'an' is located in the answer.
'liberal' could be 'l' (abbreviation) and 'l' is found within the answer.
The remaining letters 'ca' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
'to' is the link.
(Other definitions for canal that I've seen before include "navigate this?" , "Man-made channel of water" , "Man-made watercourse" , "Artificial waterway for barges" , "Artificial waterway as at Panama (5)" .)