Presumably, they're canvassing to get into Government by organising a go-slow (7,2,4)
I believe the answer is:
working to rule
'organising a go-slow' is the definition.
'presumably they're canvassing to get into government' is the wordplay.
I cannot really see how this works, but
'to' is found in the answer.
'get' could be 'work' ('work' can be a synonym of 'get') and 'work' is located in the answer.
'into' could be 'in' and 'in' is found within the answer.
'government' could be 'rule' (I've seen this before) and 'rule' is found within the answer.
A single letter 'g' remains which might be clued in a way I don't understand.
This explanation may well be incorrect...
'by' is the link.
Can you help me to learn more?