For weeks, Fukushima has threatened to undermine what, in other respects, has always appeared a strong bid.

So it was the message delivered by Prime Minister Shinzo Abe that was the most important element of its presentation.

Confronting the issue unprovoked and head-on, in contrast to the bid's approach when its prospects seemed to be floundering, Abe told International Olympic Committee (IOC) members:

"Some may have concerns about Fukishima.

"Let me assure you that the situation is under control.

"It has never done, and will never do, any damage to Tokyo."

Abe returned to the subject later in considerably more detail, in response to a question from Norway's Gerhard Heiberg, a senior IOC member.

In spite of a glitch with the translation system, his words came across once again as strong and unhedged: in summary, "Don't believe everything you read in the papers, and, by the way, I take full responsibility for the future safety of Japanese citizens and visiting athletes".

A colourful and bubbly presentation had three further strong-points.

The appearance of Princess Takamado has been a boost to Tokyo 2020, a bid confronted by a barrage of questions over the situation regarding Fukishima

First and foremost, the introduction delivered - in French and English - by Princess Hisako of Takamado, whose very arrival in the Hilton lobby, as a member of the Japanese Imperial Family, had provoked a sensation earlier in the week.

The Princess's presence and her evident relish at embarking, once in situ, on a busy lobbying schedule, meant that, at a stroke, IOC members - the electorate - stopped talking about Fukishima during the most important hours of the campaign.

Her pitch-perfect introduction on stage today was another major contribution to the bid's improving prospects.

Next up, was not a man in a suit, as it surely would have been in previous Japanese Olympic bids, but a female Paralympian, Mami Sato.

What is more, she came equipped with a particularly winning anecdote, highlighting the human side both of disability - Sato lost a leg to cancer - and, once again, the tsunami.

Tokyo 2020 chief executive Masato Mizuno speaks during the bid presentation

Finally, a two-part film, drawing much of its flavour from London 2012's groundbreaking presentation in Singapore in 2005, told the story of a small boy playing hoops by himself in the middle of nowhere when his ball became lodged beside the makeshift basket far out of his reach.

A passing bus-load of pro basketball players with American accents retrieved the ball, showed him some moves and left him with a scarlet sweat-band and the salutation, "See you in the pros some day".

All perfectly preposterous, of course - and let's just say it was no surprise when the sweatband, and the boy as adult, cropped up again later on when the second half of the film was shown - but the emotional impact was none the less powerful for that.

As I write this, with three hours to go until IOC members pronounce their verdict, Tokyo looks right back in the hunt.