Rail passengers often have to stand on their daily commute

The campaign group said more capacity was needed if commuters from Woking were to get a better deal.

One of its researchers, known as Sardine Man, travelled on the route this week at the start of a campaign highlighting overcrowded rail journeys.

South West Trains said it had already introduced 12-carriage trains.

We accept that we have a challenge, and it's one that we're happy to take on Phil Dominey, South West Trains

But Julia Thomas, Transport 2000's public transport campaigner, said even longer trains were needed on the route, despite there already being 12 trains an hour at peak times.

She said figures predicted the number of rail passengers would increase by 30% over the next 20 years.

"Clearly we need to plan for that kind of growth."

Phil Dominey, of South West Trains, conceded Woking was a key station and said everything possible was being done to increase capacity.

Sardine costume

He said 12 carriages had now been introduced on 50 trains on the Portsmouth to London line, which goes through Woking, giving 142 extra seats on each one.

Additional capacity had also benefited the line running from Bournemouth, he said.

"As a result of our improved train performance more people are using our trains... we accept that we have a challenge, and it's one that we're happy to take on," he said.