By Karolos Grohmann
Aug 31 (Reuters) - The race for three cities hoping to land the 2020 summer Olympics will go down to the wire after two years of campaigning as Istanbul, Madrid and Tokyo grapple with their own problems ahead of the Sept. 7 vote.
The International Olympic Committee will elect the winning bid at their session in Buenos Aires, Argentina, next month with no clear front runner in the campaign to host the world's biggest and most expensive multi-sport event.
With bid leaders of the three cities preparing for their final pitch in Argentina, backed on site by political leaders and a string of celebrity supporters, senior IOC officials say the race has never been so open.
"It is not like before when the decision has often been made," IOC Vice President and presidential hopeful Thomas Bach said days ago. "This time I think the presentation (in Buenos Aires) will be very important, crucial even."
Each of the three cities have long highlighted their own assets and the advantages they bring to the Olympic movement should they be chosen to succeed 2016 Rio de Janeiro as the next summer Games hosts.
Istanbul is pitching Games on two continents - the European and Asian parts of the metropolis - as Turkey, with its growing economy, hopes to become the first country with a majority Muslim population to get the Olympics.
Japan's Tokyo, looking to host them for a second time after 1964, is branding its bid as a safe and solid choice amid financially turbulent times as it incorporates some venues from their first Games to its new proposal.
Madrid, campaigning for the third straight time, is playing up its high percentage of existing venues, placing sport at the very heart of their bid.
The choice the 100-plus IOC members will make, however, is likely to also depend on non-related Games issues.
Istanbul, making its fifth attempt in the last six votes, was rocked by violent anti-government demonstrations in June that spread to much of the country, shaving off some of the bid's momentum up to that point.
Protests may have subsided for now but with Prime Minister Tayyip Erdogan likely to travel to Argentina to back the bid, questions on discontent in the country will be all but inevitable.
The escalating conflict in neighbouring Syria, and fears it could spill over in the region, are not unfounded as the United States contemplate a military intervention.
Istanbul bid officials as well as the IOC have played down these fears saying Turkey can handle the security situation and that protests have died down.
Turkish bid officials also argue the Syrian border is a long way away from Turkey's largest city, wedged between the Black Sea and the Sea of Marmara, bridging Europe and Asia.
A string of positive doping cases among Turkish athletes has been a further hit for the bid, even if it does not want to admit it.
"What happened in Turkey with the protests and doping is something that I want to connect in a positive way," Istanbul bid chief Hasan Arat told Reuters earlier this month.
"The protests are over in Turkey. There is no problem any more, this is not a fundamental problem for Turkey. On the doping side we are cleaning up, there is zero tolerance. It is a very clear message for drug cheats in Turkey."
Spain has been in and out of recession since a decade-long property bubble burst in 2008 and, with unemployment at around 27 percent, is expected to remain in an economic slump for at least another year.
Prime Minister Mariano Rajoy also admitted a corruption scandal, which has undermined the authority of Spain's ruling People's Party (PP), has hit the country's image abroad.
Rajoy was testifying about his involvement in the scandal which centres on allegations his party collected millions of euros in cash donations which were then distributed to senior PP figures, including himself.
That is unrelated to the Games in seven years' time, Madrid officials will argue.
Tokyo, which failed to land the 2016 Olympics and is seen by some as having a slight advantage over its rival bidders, may be advertising its bid as a solid choice for the IOC, but the 2011 deadly earthquake and subsequent nuclear disaster at Fukushima is still a top news story.
With highly radioactive water spilling into the ocean and Japan raising the severity level of the latest leaks, it is news that Tokyo does not need days before the vote.
"As far as hosting the Games, the situation in Fukushima will not affect Tokyo," said Tokyo governor Naoki Inose last week. But with the current leak being the fifth and worse since the disaster, it is difficult to predict how the situation will develop in the coming years.
An IOC evaluation report released in June offered few clues on potential frontrunners, with all three bids being "of high quality", putting the decision firmly into the hands of the IOC membership, who will vote after that final - crucial - presentation. (Reporting by Karolos Grohmann; Editing by Ossian Shine)