London had been joined by Edinburgh and Manchester in seeking to be the site of what is officially known as the Grand Départ for the 2017 event.
On Monday evening Transport for London (TfL) said it had been chosen but had declined the offer after deciding the cost of staging the event did not represent value for money. The French company which organises the Tour, ASO, was reportedly told of the decision last week.
Johnson said the choice was “entirely my call”. He said: “I had to take a very tough decision, obviously painful. In an ideal world, you know me, my policy is to have your cake and eat it.
“The difficulty was we had to make a choice – £35m is an awful lot to spend on a one-off event when you could put that money in to long-term projects. What people really want is safer cycling lanes.” He added: “For me it was a no brainer.”
Speaking separately to BBC London radio, Johnson said: “I will not waste cycling money on something that would only deliver very brief benefits.”
The 2017 start has instead been awarded to Germany.
It is understood that a London-based Grand Départ would have seen the race spending more than one day in and around the capital, much like the hugely successful two days of racing in Yorkshire which kicked off the 2014 Tour.
The £35m cost would partly involve a direct payment to the Tour organisers, with the rest covering the costs of the associated disruption to the city over two days of road closures and re-routed transport.
The decision to refuse happened because of a lack of outside funding, according to Isabel Dedring, London’s deputy mayor for transport.
She said: “The mayor has always made it clear that he was supportive of the Tour coming to London subject to funding being available. There were extensive discussions, internally and with government, on finding the requisite £35m but in the end a funding route could not be found.
“The only option would have been to take it from the budget dedicated to cycling improvements in the city, which we were not prepared to do.”
Johnson’s administration is currently amid an ambitious scheme to boost the numbers of cyclists in London, including the ongoing construction of two so-called superhighways going across the capital, which segregate riders from motor traffic.
Speaking on Monday Leon Daniels, TfL’s managing director for surface transport said London’s previous hosting of the Grand Départ, in 2007, had been “amazing”, but could not be repeated due to financial considerations. He said: “We have always said that the return of the Tour was subject to funding.
“To ensure value for money we must make difficult choices, and on this occasion we have decided that we will not be hosting the Grand Départ in 2017.”
The process of seeking to host the Tour start is not a formal bidding process, as with something like the Olympics. Instead, would-be host cities and regions have more informal discussions and correspondence with Tour organisers.
Chris Boardman, the former Olympic and Tour de France cyclist, who is now policy adviser to British Cycling, said he could understand the decision. “Don’t know the details but if I had to choose, I’d spend it on infrastructure as well,” he wrote in a tweet. He added: “That said, why bid in the first place?”
This article was written by Peter Walker, for theguardian.com on Tuesday 29th September 2015 15.36 Europe/Londonguardian.co.uk © Guardian News and Media Limited 2010