Extra trains will be put on over the Olympics after an MP expressed concern about overcrowding.

Brighton Pavilion MP Caroline Lucas said rail companies must plan now to ensure the Sussex rail network can cope with London 2012.

Southern said to meet the predicted sharp rise in demand it will run additional late night services from London Victoria to Three Bridges, Worthing, Eastbourne, Gatwick Airport and Brighton.

Dr Lucas, who wrote to Southern Rail and First Capital Connect to raise the issue, said: “I’m concerned that the transport discussions so far have focused very much on London and on behaviour change from passengers, rather than on enhancing services to meet increased demand.

“There will be a huge increase in rail passengers around events like the Box Hill road cycle race and the torch relay which comes to Brighton and Hove on July 16 – and for visitors to the Olympiad’s Stories of the World project.

"I want to know what FCC and Southern are doing to address the disruption and overcrowding on train services between London and Brighton that will doubtless occur as a result of these events.”

Southern said it expects “higher numbers” of passengers during the Olympics and Paralympics.

A spokeswoman said extra staff and volunteers will be deployed to help at busy stations.

She said increased services will run for the cycle races on July 28 and 29 and there will be additional Hastings to Ashford services for the torch relay.

To increase space both Southern and FCC is extending its current bicycle policy so full size bikes will not be allowed throughout the day during the Olympics between London Victoria and Brighton, rather than just at peak times.

A FCC spokesman said data shows departures between 9am and 10.30am are likely to be the busiest and urged passengers to spread their journeys.

He added: “We will be utilising our train fleet to provide the maximum capacity we can during the Olympics.”