LONDON (AP) ― Exactly eight months before the vote, the race for the 2020 Summer Games moved into a crucial phase Monday when the three candidate cities submitted their bid plans to the International Olympic Committee.

Leaders from Istanbul, Madrid and Tokyo handed over their documents at IOC headquarters in Lausanne, Switzerland, setting the stage for the final months of an international campaign featuring three cities bidding again after previous defeats.

At a time of continuing global economic uncertainty, Madrid is bidding for a third consecutive time, Tokyo a second time in a row and Istanbul a fifth time overall.

The so-called “bid books” run to several hundred pages and represent the cities’ master plan of venues, budgets, financial guarantees, security, accommodations, transportation and other key aspects of the multi-billion-dollar projects

The files are to be released publicly by the bid cities on Tuesday.

The IOC’s evaluation commission, headed by Craig Reedie of Britain, will visit the cities in March and prepare a report for IOC members before a meeting with the bidders in Lausanne in July. The full IOC will select the host city in a secret ballot in Buenos Aires on Sept. 7.

The 2020 field initially included six candidates, but Rome dropped out when the Italian government refused to offer financial support and the IOC cut Doha, Qatar, and Baku, Azerbaijan, from the list last year.

The mayors of Madrid and Istanbul, Ana Botella and Kadir Topbas, joined their bid teams for Monday’s ceremonial handover. Tokyo brought football star Homare Sawa, the FIFA women’s world player of the year in 2011.