Olympics: Countdown To Opening Ceremony

A potential worldwide audience of billions are about to watch the Olympic Games get under way tonight with a £27m opening ceremony.

The Isles of Wonder spectacular will welcome the world to east London as the build-up of the last few months becomes a reality.

Ceremony director Danny Boyle has dedicated the extravaganza to the 15,000 volunteers helping to bring it to life as organisers said they expected a sell-out crowd of 62,000 in the audience at the Olympic Stadium in Stratford.

He said: "This is a live performance and it's the actors, and in our case they're volunteers, who have to get up there and do it."

Speaking at the Olympic Park, the Oscar-winning filmmaker added: "It's been a long road and we're almost there. I'm looking forward to it very much."

Organisers Locog said just 50 tickets were left for the ceremony, which starts at 9pm.

Earlier thousands of people lined the River Thames to cheer the Olympic torch as it made its way across London to the end of its journey.

This morning bells rang out around the UK to mark the final countdown. London's Big Ben was joined by hundreds of churches across the nation as it chimed non-stop for three minutes to ring in the Games.

Prime Minister David Cameron said Britain was ready to welcome "the greatest show on Earth", telling reporters: "We have got a great past, a very exciting future and this is a great moment for our country, so we must seize it."

Mayor of London Boris Johnson told Sky's Adam Boulton the build-up to the Games had been an "amazing thing".

"You're seeing a kind of benign contagion passing from person to person," he said. "Not necessarily infecting everybody... there are some people who remain impervious to the joy of the torch and I can understand that.

"But it is a wonderful thing to see."

Many of those heading towards the Olympic Park were beset by transport problems, with main line train and Tube delays causing hold-ups in and around the capital.

Culture Secretary Jeremy Hunt was also involved in a mishap. He narrowly missed injuring bystanders as he rung an Olympic bell and its handle flew off during celebrations on the banks of the Thames.

He later told Sky News the Games were "the longest single advert for Britain in our history".

Mystery still surrounds who will be given the honour of lighting the Olympic flame,

The Queen, Sir Steve Redgrave, Sir Roger Bannister, Daley Thompson and David Beckham have all been touted as contenders.

Beckham made a surprise appearance at London's City Hall, where the torch relay neared the end of its journey, and spoke of his pride at helping to bring the Games to his home turf.

The 37-year-old, who was raised in east London, said: "Today is going to be an amazing moment."

Anticipation has bene growing among the crowds visiting the Olympic Park.

American sports fan Rod Coffee, from Miami, told Sky News: "It has already outlived my expectation you guys have done an amazing job."

Antonia Nkemnacho, who lives in Stratford, added: "I am very pleased to be welcoming the world, you don't feel like going to the West End now because what we have here makes you feel proud."

Although the early rounds of some competitions are already under way, tonight's show gives the athletes a chance to announce their nation's arrival at London 2012.

Jamaican 4x400m relay runner Dominique Blake told Sky News: "It is just a really amazing sense of pride that you carry and it is a memory you will remember for the rest of your life. It's awesome!"