An International Olympic Committee report on the three cities wanting to host the 2020 Summer Olympics indicated there was no clear favourite among the bids from Madrid, Tokyo and Istanbul.
"In presenting this technical report, the 2020 Evaluation Commission wishes to record that the projects of the three candidate cities are of a high quality and that each city offers a unique approach to organising the Games," the IOC said.
The struggling Spanish economy was of no risk to Madrid, security in Turkey did not threaten Istanbul's chances and Tokyo's low public support was offset by praise for the bid's financial strength, the report said on Tuesday.
The winning city will be selected at the 125th IOC Session in Buenos Aires in September. The report comes before a crucial meeting in Lausanne on July 3-4 when the bid cities will present their plans to the entire membership of the IOC.
Unlike past evaluation commission reports, there was no rating of the bid cities or overall summary which could point to a frontrunner in the race to host the world's biggest multi-sport event.
Istanbul, bidding for the fifth time in the last six votes, received a thumbs-up for government backing, wide public support and its capability to deliver construction for the Games on time.
"The Commission is confident that given the government's full support and the proven track record of (state construction company) TOKI to date... construction works could be funded and completed on time."
Travel times to venues, however, were rated as somewhat optimistic given the city's traffic issues but Istanbul has also significantly improved public transportation in the past 20 years.
"We are very delighted with this report," bid chief Hasan Arat said in a conference call. "When you look at all our five bids this is the best.
"The report has highlighted many of our key assets, in particular, our robust and proven delivery solution and the significant government, private sector and general public support for the Games."
The report was drafted before nationwide protests against the government of Prime Minister Tayyip Erdogan. During unrest since late May police have used force against campaigners opposed to plans to redevelop a central Istanbul park.
"I don't think it (protests) will continue for a long time because their message is very well received," said Arat. "There have been some pictures which we did not want to see. But it happened and we look forward to a better Turkey, better understanding, better democracy."
The report noted the country could successfully safeguard the Games despite security problems with neighbouring Syria and the Kurdistan Workers Party (PKK) guerrillas.
The issue of the Turkey protests and the police crackdown are expected to be talking points at July's Lausanne meeting.
Tokyo, which failed to beat Rio de Janeiro for the right to host the 2016 Olympics, has already created a $4.5 billion reserve fund for the Games, a major asset in its bid, the IOC said.
"Despite a significant construction programme, the Commission is confident that work could be completed on time and that Tokyo has the necessary financial strength to do so through the TMG's "Hosting Reserve Fund" of $4.5 billion, earmarked for venue construction," it said.
"The Commission is confident that the Japanese economy would be able to support the necessary infrastructure development needed for the delivery of the Games." The Japanese capital, however, is lagging behind both its rivals in public support.
"We are proud that the report confirms our bid's very strong technical excellence, which offers certainty in uncertain times for sport," said Tokyo bid leader Tsunekazu Takeda, who is also an IOC member. "There can be no doubt that we will deliver and offer the IOC a strong partnership."
Madrid won high marks for its compact bid in its third straight attempt to land the Games, with no major investment in venues or transport needed due to the city's existing infrastructure.
Spain's economic recession also represented no major risk to the Games should the city be selected, the IOC said.
"The Commission believes that the degree of financial risk facing Madrid 2020 should be manageable over seven years within the overall Spanish economy and taking into account government guarantees. All required financial guarantees were provided," it said.
It did note that overlay work would be needed for some existing venues while the use of some landmarks in Olympic competitions could prove to be a challenge.
"When (we) made the shortlist in first place (last year), this was the first step towards knowing how we were doing," said bid leader Alejandro Blanco. "Now we have managed to achieve this result with a report that is truly spectacular."
Image: IOC President Jacques Rogge
Photograph: Jeff J Mitchell/Getty Images