Osborne compared his lack of contact with the advertising industry as chancellor to sectors such as finance and automotive, which he spent much more time with because they are more closely regulated.
Speaking at the Advertising Association's summer drinks reception at J Walter Thompson London, Osborne said the advertising sector is an "incredibly important industry" and "shouldn’t be shy about making your voice heard".
Osborne said: "Make sure the advertising industry has its voice heard and don’t be afraid to spell out what you think are the consequences if those interests are not taken into consideration.
"I’m afraid it’s going to require you to make your voice loud as I suspect as the government is buffeted from one turn in the negotiation to another. It’ll be the industries that are really about to articulate their concerns which will find those concerns at the top of the agenda."
The AA has set up a Brexit Taskforce to coordinate its efforts on the country leaving the European Union. James Murphy, group chief executive of Adam & Eve/DDB and chairman of the AA, is chairing the AA’s Brexit Taskforce.
The taskforce is working with the CBI and Creative Industries Council and has already met with the Department of Culture, Media & Sport, the Department for Business, Energy & Industrial Strategy, HM Treasury and the Department for International Trade.
Andy Duncan, the former managing director at Camelot and president of the AA, said the organisation was focusing on three major areas: talent and the impact of Brexit, encouraging businesses to use advertising to drive growth and how the advertising industry manages data.
Explaining his switch from politics, Osborne – who announced he would step down as an MP in April, some weeks after he was appointed editor of the Evening Standard – joked: "I needed to get out of a profession where we exaggerated the truth, made claims we could never stack up and engaged in personal name-calling. And so I went into journalism."
He continued: "The reason I’m here is I couldn’t do what I do now without your support, without the help of the people in this room. London’s Evening Standard is distributed free of charge. We don’t have any subscribers. We don’t have a cover price."