Commuters could be whisked to Waterloo on double-decker trains as part of Network Rail plans to accommodate millions of extra passengers over the next 30 years.

Ideas the group is considering, alongside South West Trains (SWT), also include extra tracks between Surbiton and Clapham Junction and increasing speed limits to 125mph - but watchdog groups have said value for commuters' money must be a priority.

A new public consultation was launched today and will run for three months, allowing passengers to air their views on what should be done to bolster an often unreliable and overcrowded service.

Tim Shoveller, representing National Rail and SWT, said: "The plans we are proposing in this study mean we will be able to cope with a forecast growth of 40 per cent on main line services over the next 30 years.

"We are also looking at what kind of improvements we can offer in reliability and frequency by introducing new technology.

Revamped services in the "Wessex route" area, that includes Kingston, Hampton Court and Epsom, could provide benefits for London alongside Crossrail 2, according to details released this morning.

A number of changes to signalling are also mooted.

The proposals may go some way to appease travellers who routinely suffer shorter-than-expected trains, delayed services and signalling problems.

A spokesman for London TravelWatch said: "Proposals for double decker trains would address capacity issues, as will increased frequency of suburban rail services, something we have been advocating for a number of years.

"But all this needs to be tempered by ensuring passengers get value for money which has to be a short term priority.

"Research shows that passengers view value for money on rail services as the number-one priority for improvement."

  • Find out more about the proposals, and have your say, by clicking here.