Tony Blair and David Beckham have attended a ceremony to mark the "topping out" of Wembley Stadium.
Londoners say they preferred the stadium's old twin towers
The stadium's arch was lit up on Wednesday to celebrate the building reaching its full height.
The structure is 133 metres high - virtually allowing the London Eye to roll underneath it - and can be seen from across the capital.
The stadium, which is hoped to boost Britain's chances to host the Olympic Games, should be ready by spring 2006.
In his speech, the prime minister said this was going to be "the most spectacular stadium in the world".
Facts about the arch
133m high and 315m wide
Weighs 1,750 tonnes
Can be seen from 13 miles
Stands more than four times higher than the old twin towers
Took six weeks to lift into place
"This particular piece of ground has a special place in everyone's heart and Wembley has a special kind of magic," he added.
He said that part of the profits would go back to the local community and be invested in grassroots sport.
"It's not just a great stadium - it's in a locality and local people want something back out of having the new Wembley stadium here."
The topping out ceremony of the arch marks the end of the four-stage lifting process.
It will eventually support much of the new stadium's roof structure.
To the sound of Jupiter from Gustav Holst's The Planet Suite, the prime minister and the England captain triggered a fireworks display that lit up the north-west London sky.
The 1,750 tonne arch is four times the height of Wembley's long-gone but world famous twin towers.
On Tuesday, in a BBC poll for BBC London, members of the public voted that they preferred the towers.
But the stadium's architects are positive that the arch will become as much a part of English football as the three lions.
England captain David Beckham said: "As a national captain I think it's very exciting to have an England stadium.
"England deserves it and all the fans deserve it because Wembley was part of our history - it's where we won the World Cup, and I'm looking forward to the next game we play here."
The London Eye could fit underneath the 133m high arch
At the ceremony, the England manager and captain also began the national team's campaign to qualify for the World Cup in Germany in 2006.
On Thursday the team will fly to Austria for a qualifying match.
Now all hopes are pinned on the new landmark's role in winning the bid to host the 2012 Olympic Games.
Wembley National Stadium Ltd chief executive Michael Cunnah said: "It's incredible to think that only a few England home internationals remain until the England team return to Wembley.
"Wembley is also a major part of Britain's 2012 Olympic bid, and this is the perfect opportunity to show our support."