LAUSANNE, Switzerland -- With the voting just over two months away, the bidding for the 2020 Olympics and the race for the IOC presidency are reaching a pivotal stage.

Both campaigns come together this week in Lausanne as the three bid cities and six presidential candidates make vital presentations to the voters - the 100-plus members of the International Olympic Committee.

Istanbul, Madrid and Tokyo make their pitches to the IOC assembly on Wednesday, with the Turkish city having the most at stake following the wave of anti-government protests that swept the country. The presidential contenders present their platforms to the members on Thursday.

Both events could prove decisive going into the final weeks before the IOC session in Buenos Aires, Argentina, where the members will vote by secret ballot for the host city on Sept. 7 and the new president on Sept. 10.

The presentations will be made behind closed doors at the Beaulieu convention center. The bid cities will each have 45 minutes to make their case, with another 45 minutes allotted for questions and answers. The presidential candidates will each have 15 minutes to outline their manifestos.

Overseeing the proceedings will be IOC President Jacques Rogge, who steps down in September after 12 years in office. He served an initial eight-year term and was elected to a second four-year mandate.

Vying to succeed Rogge are: IOC vice presidents Thomas Bach of Germany and Ng Ser Miang of Singapore, executive board members Sergei Bubka of Ukraine and C.K. Wu of Taiwan, and former board members Richard Carrion of Puerto Rico and Denis Oswald of Switzerland.

The presidential race is generating more buzz than the 2020 contest among the members.

"Basically the most important thing we do is to elect a president," senior Norwegian IOC member Gerhard Heiberg told The Associated Press. "It's more important than organizing cities for the games. We have many challenges coming.

"We will elect a person for eight years. This person will mean a lot of difference in the IOC, the thinking, the strategy. I meet a lot of IOC members and they talk about nothing else."

Bach has been considered a front-runner, but favorites don't always win in the unpredictable world of IOC elections.

All six candidates have already sent their campaign platforms to the members. Now the voters will get a chance to see and hear them in person, the first time such presentations have been organized for an IOC presidential campaign.

The six will speak one after the other. It is not a debate and no questions will be allowed. The IOC says it wants to keep the format to a controlled, civil campaign.

"They have 15 minutes to stand in front of the session, to show their personality and to lay out their programs for the eight years coming," Heiberg said. "This will give a good indication, especially for members who don't know the six, to finally get to see them performing."

The candidates' platforms have steered away from revolutionary change and centered on common themes: reaching out to youth, stepping up the fight against doping, reviewing the bidding process for the games, improving the system for selecting sports on the Olympic program, raising the 70-year age limit for IOC members.

"The race really starts this week," Heiberg said.

By contrast, the 2020 bid cities have been campaigning for nearly two years already, but this will be the first time they appear before the IOC assembly. All three are bringing high-ranking delegations to try to earn the members' trust and confidence.