A DRAMATIC report, which has surfaced recently from the Transport for London office, claims that the city's and the nation's economy will decline unless there is a major injection of cash to the rail network.

It states that failure to invest in the expanding system, not including the underground, could lead to the irreversible collapse of London as a major world city and international finance centre and nearly 500,000 London jobs would be lost.

And, the millions of people who travel in and to London every day will continue to suffer the misery of late and overcrowded trains.

Forecasts by government analysts show that London's public transport system will have to expand to carry 25 per cent more commuters per day by 2023 and that the population in the city will increase by more than 700,000 and the number of jobs will go up by 636,000 by 2016.

A 44 per cent increase in the total capacity of the rail networks serving London, which is already packed to the rafters, will be needed to accommodate the additional trips resulting from this growth.

Most commuters will recognise a need for improvement in the transport system but it may come as a shock that the network is in such dire straits.

So, if increasing London's rail capacity is the only truly effective long-term solution to growing transport needs, progress will have to be made through cooperation between the various bodies responsible for the railways and private sector contributions.

And TfL says it is major new projects which are key to the long-term development of London, for example, Crossrail, the East London Line Extension and Thameslink, and the upgrading of power supplies and platform lengthening. This is estimated to be in the region of £15 billion.

The London Chamber of Commerce strongly supports TfL's cause. It says investment is absolutely vital in the transport infrastructure if we are going to sustain London's business prosperity.

And, South London Businesses are in favour of the future investment plans.

A spokesman said: "We fully support Transport for London's case for the prioritisation of additional investment in London's railway infrastructure. Business cannot survive if our railway infrastructure is continually neglected. We have been arguing for some time that the cost effective movement of goods and services around London is vital to the future of our economy, and the longevity of our local businesses.

"There is an overwhelming business case for the development of our railway infrastructure. What we need from Gordon Brown is a firm commitment to prioritise funding for Crossrail, Thameslink 2000 and the East London Line Extension."

The pleas for extra cash have been met with some opposition. It is believed there are alternative means of finance for the future. Some may say this forecast of meltdown is exaggerated and others believe the system is already in a state of collapse.

Cllr Tony Arbour, Conservative leader of the council and the borough's GLA member, said: "Transport for London should have as its priorities, investment in bus and train rolling stock, in the infrastructure of the underground and directing resources to the overground.

"For thousands of commuters in south west London, whose trains are late, filthy and overcrowded, meltdown is already here.

"A Conservative run TfL would not toy with expensive and ill-thought out proposals like the Crossrail link to Kingston. Local residents would prefer to see that proposed investment spent on improving what we already have and wish the District Line to be extended instead.

"Punctual, more frequent and cleaner trains are what the residents of Kingston, Richmond and Hounslow want and should have. I shall continue to work to ensure this is what they get."

While TfL is not impressed with grants received from the government, the Liberal Democrat London mayoral candidate, Simon Hughes, is asking why it has handed back £2 million to Whitehall in unspent cash.

"The mayor must explain why money that has been given to TfL for projects has gone unspent. The mayor has doubled his share of Londoner's council tax in the last four years, but is happy to give the Labour Government back money.

"Every year, Transport for London fails to spend all the money it has been given by the government. Only this week, TfL warned London about the future meltdown of our transport infrastructure. It is astounding that TfL is failing to spend every last penny it is allocated by central government."

The rail union RMT is strongly opposed to private financing. It maintains that it was the private sector who plunged the network into this mess in the first place.

A spokesman said: "The railways should be financed from the public purse. Huge profits are being taken out of the industry and that is part of the problem. Balfour Beatty have recorded a huge increase in their profits putting it down to the 1.2 billion contracts for London underground. Private finance is very expensive. We say get the privateers out of financing."

TfL concludes that the options are stark and simple - either suppress London's economic growth and face the consequences, or invest in its rail infrastructure and the future prosperity of London and the UK.