The organisers of the London Olympics have scrapped part of the opening ceremony to ensure that it finishes in time for people to catch public transport home.

Organisers LOCOG said a sequence involving stunt bikes had been cut from the spectacle at the Olympic Stadium in east London, which kicks off the Games on 27 July.

"We need to make sure the show comes in on time to make sure spectators can get home on public transport, so we have taken the tough decision to cut a small stunt bike sequence of the show," a LOCOG spokesman said.

He added that the £27-million ceremony was due to finish between midnight and 12:30 am, around the time when London's Underground train system shuts for the night.

The show is designed to transform the stadium into a rural British idyll, complete with cows, sheep and synthetic clouds to provide traditional British rain - in the unlikely event that the weather does not provide it.

Sports minister Hugh Robertson denied that the decision to cut part of the opening ceremony had anything to do with a furore over the failure of private security company G4S to supply thousands of guards for the Olympics.

The government has had to step in and deploy an extra 3500 military personnel to cover the shortfall, and Robertson said there were contingency plans to draft in a further 2000.

But he said of the curtailed opening ceremony: "The decision has got nothing to do with G4S and security. It is all about finishing between midnight and 12.30 am.

"It is absolutely a transport concern."

The ceremony's artistic director Danny Boyle, whose film "Slumdog Millionaire" won eight Oscars, has said it would give Britons "a picture of ourselves as a nation".

But the British press has poured scorn on the plans, comparing the set to the one seen in the hit children's television series "Teletubbies".

One billion people are expected to watch the ceremony around the globe, while an audience of around 62 000 will see the show in the stadium.

The budget for the opening and closing ceremonies was doubled to £81-million in December, reportedly after British Prime Minister David Cameron intervened.