For civil disobedience, you can let everybody included government hear your voice quickly, but it’s a way that breaking the law and it’s will lead to violence. It is very controversial. such as India, Mohandas Karamchand Gandhi.
For petition, it’s more peaceful than civil disobedience, a Petition is formal written request. This allows us to have our opinion at least heard without having to start a protest. for example Mr. Vander Zalm petitioned to drop Harmonized Sale Tax and said people should only have to pay Provincial Sales Tax. However, petition may not represent the public because they are solicited.
Pressure groups and lobbyists are very influential. Let the government hear their voices. The assembly of First Nations has been successful in the past with their pressure groups. As well as implementing NAFTA in North America which has benefitted so many people in Canada.