The Mayor has hit back at critics of the Hammers' move to the 54,000 seater arena in Stratford insisting the decision to hand the keys to the East Londoners was one the biggest and best of his tenure in office.
'West Ham fans are part of something that will change the face of London'
Speaking to the club's official website at a special event to mark 10 years since London was awarded the 2012 Games, Johnson warned Europe's elite that West Ham are set for big things.
"This is just the beginning," Johnson told whufc.com.
"I think people will look back, everyone involved with West Ham, everyone who supports West Ham, I think they will be very proud, actually, that they are part of something that is the biggest economic social regeneration project anywhere in Europe.
“I think West Ham fans are part of something that is going to change the face of London, bring the two halves of London closer together.
"The East and West of London are converging in a way that we haven't seen for hundreds of years maybe."
A turbulent journey of justification
Fears that the huge stadium would turn into an expensive white elephant once the dust had settled on the London 2012 Olympics were seemingly allayed when the Premier League side were handed the keys to the iconic ground as anchor tenants in 2013.
But legal challenges to have the decision thrown out from the likes of Spurs and fellow East Londoners Leyton Orient marred the process and saw the Hammers' legitimacy to take over the running of the stadium called into question.
The club has continuously been forced to defend the deal, firstly moving to quash suggestions it contravened domestic or European legislation and does not constitute state aid.
Then more recently despite arguing it could be damaging to their bargaining position to drive the best possible contracts from suppliers and service providers, the Hammers had to accept the publication of the full financial details of the deal, as reported by Sky Sports.
The relatively small amount of money the Hammers will have to pay towards conversion costs to make it a suitable all-seater arena for football has also received negative publicity.
'The only way was the West Ham way'
But Johnson went on to defend the transformation - which has been headed up by West Ham's owners David Sullivan and David Gold and the chief executive Karren Brady - saying it was the only viable way forward for the stadium.
He added: "The biggest decision I had to make when I became Mayor was what are we going to do about this stadium, because if you remember the plan was to have an athletics Stadium, take down the top tiers and have a 25,000-seater bowl, which basically would have been a dust bowl for most of the year, because not enough people go to watch athletics.
“Or to knock it down completely, which would have been a complete waste of about £400million or to spend some more money, £272million to be exact, on the biggest cantilevered roof anywhere in the world and to turn it into a truly world class stadium."
The Mayor's staunch defence of West Ham's Olympic Stadium deal will come as a welcome boost to supporters who have barely had the chance to enjoy the prospect of next summer's historical move.
Perhaps now those fans can start to dream of a very bright future in their new home.