Commuters from Brighton and Hove can expect more overcrowded train journeys during the morning and evening rush hours in the next four years.
The number of seats on journeys to and from London is not likely to improve before 2014 and, as passenger numbers rose, conditions may worsen.
The warning comes in a report by MPs on the House of Commons Public Accounts Committee.
It says: “The Department for Transport is 18 months into a five-year £9 billion investment programme to improve rail travel, in particular by increasing the number of passenger places on trains by March 2014.
“This was to be achieved by a combination of longer platforms and other station improvements and more carriages coming into London and other major cities during peak hours.
“The department is responsible for securing the extra places on trains from train operators.
“The Office of Rail Regulation is responsible for ensuring Network Rail delivers infrastructure efficiently.
“The department’s latest plans show that all the relevant targets will be missed.
“There will be 15 per cent fewer extra places delivered in London in the morning peak and 33 per cent fewer into other major cities compared to the numbers the department stated would be needed just to hold overcrowding at current levels.
Rising demand
“Despite the impact of the present economic downturn on journey numbers, we are concerned that the failure to meet the targets set will lead to substantial increases in already unacceptable overcrowding levels by 2014 and beyond.
“Rising demand for rail travel combined with serious cuts in public expenditure make it imperative that the rail industry becomes more efficient, otherwise the passenger will suffer.
“The department told us that levels of crowding, and ticket prices, depend on policy decisions about the level of government subsidy.
“We are strongly of the opinion that this view is misguided as it ignores the scope for efficiency savings to release resources for frontline services.
“The industry’s ability to provide a good quality rail service, including acceptable levels of crowding, depends crucially on the efficiency of all players in the rail industry, and of Network Rail in particular.
“Rail infrastructure costs more in Great Britain than in other countries.
“The regulator has been in existence for more than a decade yet he still accepts that there is still ‘a very large potential for Network Rail to improve its efficiency’.
“The regulator’s ability to drive efficiency in Network Rail is limited by a lack of transparency of Network Rail’s costs which, it seems to us, is compounded by the regulator’s lack of urgency and effectiveness in challenging Network Rail’s efficiency at a detailed level.
“Network Rail is a company without shareholders and is the monopoly provider of rail infrastructure.
“It is vital therefore that its costs are scrutinised and challenged robustly and independently on behalf of Parliament and taxpayers.
“The National Audit Office is ideally placed to do this.”
Civil servants blamed
The Association of Train Operating Companies (ATOC), which represents Southern and the Thameslink operator First Capital Connect, blamed civil servants and Network Rail for the outlook on overcrowding.
A spokesman said: “Sustained and targeted investment to reduce overcrowding is vital if we are to deal with the growing number of people that want to travel by train.
“Demand for rail travel has bounced back strongly since the recession and is expected to double over the next few decades.
“The delay in tackling capacity has coincided with the growing involvement of civil servants in buying new trains.
“The best way to get value for money and ensure extra capacity is delivered when and where it is needed would be to return to a situation where train operators take a greater role in ordering new rolling stock.
“In the early days of privatisation, train operators successfully ordered nearly £5 billion of new trains.
“The committee is right that the rail industry has to become more efficient.
“Train companies have argued for longer, smarter franchises which would allow them to tackle overcrowding more quickly and cheaply by giving them more scope to innovate and bring in private sector investment.
“Reform is also needed for Network Rail to become more commercially minded and focused on passengers.”