Barge in front of canal has great horses around (4-5)
I believe the answer is:
gate-crash
'barge in' is the definition.
('gate-crash' can be a synonym of 'barge in')
'front of canal has great horses around' is the wordplay.
'front of' says to take the initial letters.
'horses around' is an anagram indicator.
The first letter of 'canal' is 'c'.
'c'+'has'+'great'='chasgreat'
'chasgreat' is an anagram of 'GATE-CRASH'.
(Other definitions for gate-crash that I've seen before include "Go to party without being invited" , "Enter (a party) without an invitation" , "Attend private party without invitation" , "Enter uninvited" , "Arrive uninvited" .)