London Mayor Boris Johnson has warned the Olympics could become a "skivers' charter" if London bosses don't plan ahead.
Mr Johnson was speaking at a business forum in the City alongside Transport Secretary Justine Greening MP and London 2012 chairman Lord Coe.
Londoners are being urged to consider "jog to work days" to avoid overcrowded stations, trains and buses.
Mr Johnson said: "I don't want the Olympics or Paralympics turned into a skivers' charter which everybody sits at home miserably eating hunks of cheese and drinking cups of coffee when actually if they planned and thought about their journey they could get into work."
Transport Secretary Justine Greening said: "The London Olympics and Paralympics will be once in a lifetime events and it is going to be a great time to be in London.
"Whether you are a global company or a sole trader you need to make sure you are looking at your options for travel during the Games and making sure you have the latest information on how your journeys will be affected."
Boris Johnson has also recorded a series of announcements that will be played out on the tube and other public transport networks.
In one of them, he says:
"Hi folks. This is the Mayor here. This is the greatest moment in the life of London for 50 years.
"We're welcoming more than a million people a day to our city and there is going to be huge pressure on the transport network. Don't get caught out. Get online and plan your journey at GetAheadoftheGames.com."