London Mayor Boris Johnson insisted on Sunday the city was ready to host the 2012 Olympics despite a national plunge into nervous self-depression before the excitement begins.

Johnson said Britain was feeling the necessary tension before a big performance, as the clock ticks down to Friday's opening ceremony on the Olympic Park in Stratford, east London.

He said the venues were safe and the transport system was bearing up despite a week dominated in Britain by fears over travel chaos and gaps in security.

International Olympic Committee president Jacques Rogge is in London and "he thinks that our city is as well-prepared as any city has ever been in the history of the Games," Johnson told BBC television.

"So far the traffic system and transport networks generally are holding up well."

"Possibly what we're going though at the moment as a nation, as a city, is that necessary, pre-curtain-up moment of psychological self-depression before the excitement begins on Friday when the curtain goes up."

"It is only natural that people should be tense, that they should be expectant. And, of course, there are loads of things that we need to get right."

Johnson dismissed the threat of strike action by UK Border Agency staff damaging the build-up, claiming the move was "badly supported" and most workers would want to "get behind" the Games by turning up to work.

"I don't think that whatever they do it will disrupt the Olympics or our preparations or disrupt our ability to get people through and in on time to their venues," he said.

Johnson also defied critics to say the Games were not producing economic benefits for the capital of recession-hit Britain.

"This is a gigantic schmoozathon that's about to begin," he said.

"You've got the heads of most of the world's great businesses coming to London in the course of the next few weeks. We're going to be showing what London has to offer."

England's laws restricting trading in large shops to six hours on a Sunday have been suspended for eight weeks around the Olympic and Paralympic Games.

Athletes have been getting used to their new surroundings and taking time to relax before the Games begin.

Usain Bolt, who took a trip to the cinema to watch new Batman movie The Dark Knight Rises, insisted he was ready to defend his Olympic 100m and 200m titles after recovering from a mystery problem which has hampered his preparations for London.

The Jamaican star withdrew from the Monaco Diamond League meeting citing a 'slight problem' but said he "got it checked out and it's all right".

The Olympic flame, making a seven-day tour around the capital that will culminate at the opening ceremony, was given a trip on the London Eye observation wheel.

Amelia Hempleman-Adams, who at 16 in December became the youngest person to ski to the South Pole, held the torch aloft on top of one of the wheel's capsules.

"It was amazing and just to look out and see the whole of London was incredible," she told BBC television.

"The height was quite scary."

Johnson said he had been told that more than 500,000 people turned out Saturday to welcome the torch on the first day of its tour around London.

The flame was being carried through east London on Sunday before being taken across the River Thames in a fire brigade boat to finish with a celebration where Stratford-born former world heavyweight champion boxer Lennox Lewis, was to light a cauldron.

Chinese piano virtuoso Lang Lang was to carry the torch onto the stage at the Queen's Theatre in Hornchurch.

Meanwhile Olympic bosses launched an investigation after Claudia Blunt, the daughter of prisons minister Crispin Blunt, told The Mail on Sunday newspaper that students recruited to act as stewards at the Games were fed the answers to their exam on safety.