It depends what is meant by "influence".
Council officers are there to implement council policy and in a healthy situation there is a mutual understanding of the respective roles of councillors and officers.
Having said that, if an officer believes that a decision may damage the council, there is a duty to draw this to the attention of the council and to explain what is seen as the problem. The council should allow officers a hearing. When they are fully informed of any considerations thought important by officers (and others), the council is entitled to decide, agreeing or disagreeing with the officer views.