Maurice Williamson's interference in the police case involving businessman Donghua Liu is a sackable offence.
Read more: Minister called top cop after businessman arrested for assault
A minister advocating on someone's behalf to the police is quite a different matter to advocating to the Immigration Service for someone to be given residency.
The Immigration work is an accepted part of the work an MP, especially constituency MPs, who are often confronted with cases where the rules don't accommodate deserving cases.
It has been a long-standing practice of various Governments to give the Associate Immigration Minister discretion to make final judgments on cases. The wisdom of the discretionary power resting with a minister is debated from time to time, as it has been in the wake of the Williamson-Liu case, and former Associate Minister Shane Jones using his discretion in the Bill Liu case, but that is another matter.