ATHENS, Greece — Presidents, prime ministers and heads of state from the four candidates bidding for the 2016 Olympics are welcome to attend the IOC vote next year.

The IOC had considered barring dignitaries from future votes on grounds that their presence would eclipse the proceedings.

The decision clears the way for the next U.S. president to push Chicago's bid when the IOC selects the host city on Oct. 2, 2009, in Copenhagen, Denmark. Chicago was selected as one of four bid finalists Wednesday, along with Tokyo; Madrid, Spain; and Rio de Janeiro, Brazil.

"We have debated about that, but we have the feeling we cannot stop a head of state to come to defend the bid of his or her country," International Olympic Committee president Jacques Rogge said Friday. "If they are willing to come, that's fine for us."

British Prime Minister Tony Blair was influential in lobbying IOC delegates in Singapore in 2005 on the eve of London's victory over Paris, Madrid, New York and Moscow in the vote for the 2012 Olympics.

Russian President Vladimir Putin was credited with helping Sochi secure the 2014 Winter Games when he attended the IOC session in Guatemala City last July.

While the dignitaries will be free to lobby in Copenhagen, Rogge said groundrules will be in place to keep things under control.

"We will make sure this is being handled in a proper way, an organized way," he said. "We will ban all lavish issues around that."

Chicago's bid could be bolstered by the change of administration in Washington, considering the unpopularity of President Bush around much of the world.

If elected president, Democratic nominee-in waiting Barack Obama — an Illinois senator who lives in Chicago — could be a major asset for the bid. Republican Sen. John McCain was a vocal critic of the IOC during the Salt Lake City bidding scandal in 1999.

"Both the bid and national Olympic committee have good relations with the candidates and they have expressed support for the bid," U.S. IOC member Bob Ctvrtlik said. "We will take to Copenhagen the team that has the best chance of winning the bid."

Also Friday, the IOC announced the special meeting for 2016 candidates to explain their bids to IOC members will be held July 17-18 in Lausanne, Switzerland.

That's less than three months before the vote. The cities will give 45-minute presentations on the first day, and meet with members to answer questions the next.

In the meantime, the bidders are free to begin their international promotion campaigns.

"The stopwatches are all set at zero," said Carlos Roberto Osorio, secretary general of Rio's bid. "The race starts now."