More than a third of rail passengers have to stand on trains arriving in parts of London in the morning rush hour, official figures show.
A total of 35% of commuters on services into Blackfriars stand, with almost a third standing on trains into other stations including Waterloo, Fenchurch Street and Moorgate.
Blackfriars also has the highest percentage of passengers above the official capacity for their service out of all major stations in the capital at 14% in the morning peak, the Department for Transport figures showed.
More than 580,000 passengers arrived in London by train on a typical morning peak last autumn, an increase of 3.2% over the previous year.
Crowding levels at major cities across the UK rose by 0.4% in the morning peak.
The report said: "The worsening crowding levels show that capacity provision is not coping with rising levels of passenger demand, which has been the case in London and a number of other cities."
Rail Minister Paul Maynard said: "These statistics reveal the unprecedented scale of passenger demand, with journeys doubling in the past 20 years.
"We are investing a record £40 billion into the network to address this, delivering 3,700 extra carriages by 2019 and providing a huge boost to capacity through programmes like HS2, Crossrail, and the £6.5 billion Thameslink programme.
"These projects will inevitably cause some disruption while they are carried out, which is why we have capped regulated rail fares at RPI (the rate of Retail Prices Index inflation) for this parliament and why we are working hard with Network Rail and train operators to ensure that any inconvenience is minimised.
"The end result will be new trains, better stations, and robust infrastructure to increase capacity, reduce crowding and provide better journeys for all."
The figures also show that 30% of passengers arriving at London stations between 8am and 9am have to stand, up from 26% in 2011.
This compares with 20% of passengers arriving at Birmingham, 16% at Leeds and Manchester, and 12% at Cardiff.
During the evening rush hour, between 5pm and 6pm, 17% of passengers leaving London stations have to stand, up from 14% in 2011.
The same proportion have to stand on services out of Birmingham, while 16% have to stand on departures from Leeds.
All major cities in England and Wales apart from Newcastle experienced a growth in the number of rail passengers over the past year.
In London, more than 160,000 additional passengers travelled by train compared with autumn 2011, the figures showed.
Mick Whelan, general secretary of the train drivers' union Aslef, said: "It's long been our contention that privatisation has failed to deliver for rail passengers in Britain. We're disappointed - but not surprised - by these figures.
"Disappointed for those passengers - especially those who are pregnant, or disabled - who have to suffer like this, and for those tourists who come to this country expecting a first class public transport system in a first world economy.
"Sadly, the privatised train companies are failing to deliver and this Government is letting them get away with it.
"If you're standing on your train today, then you'll be standing on your train in 10 years' time because the Government doesn't care enough to do anything about it and the companies only care about making money, not delivering a service."
The figures for overcrowding are even higher when looking just at the peak morning rush- hour of 8am-9am.
Here the proportion of people having to stand on trains arriving at Moorgate is 44%. The number for Blackfriars is 42%, Waterloo is 39% and Fenchurch Street is 34%.
In the peak evening rush-hour of 5pm-6pm, Waterloo is the worst for overcrowding, with 27% of passengers having to stand.
Passengers are now making more than double the number of rail journeys compared with 1994/95.
London and the South East accounted for around 70% of all journeys and recorded the highest growth in the past year.
The biggest number of journeys was on Govia Thameslink Railway, the country's largest franchise of Southern, Gatwick Express, Thameslink and Great Northern, followed by South West Trains.
More than a million people travelled to London on a typical day last year, compared with 125,000 for Birmingham, the next largest.
A spokesman for the Rail Delivery Group, representing train operators and Network Rail, said: "We understand passengers' frustration when they can't get a seat and we as an industry are working hard together to tackle overcrowding.
"Over the past 20 years, record numbers of passengers have been attracted to the railway, which is why we are introducing thousands of new and modern carriages."
David Sidebottom, Transport Focus's passenger director, said: "Overcrowding is a daily struggle for many commuters. Our latest rail passenger survey found that only 52% of commuters were satisfied with the amount of room they had to sit or stand on the train.
"In the long term we need a big increase in capacity. This means continued investment in new and longer trains to meet existing demand, as well as ensuring that overcrowding doesn't get worse as passenger numbers continue to increase."
Manuel Cortes, leader of the TSSA rail union, said: "These figures mean that thousands of commuters into London have to travel in cattle truck-style conditions while also paying the highest fares in Europe just to do so.
"It is a scandal that this is still happening 20 years after the failure of rail privatisation. We need a publicly-run railway with real focus on improving capacity and cutting fares."
Mick Cash, leader of the Rail, Maritime and Transport union, said: "These figures show that our rail services are dangerously overcrowded due to a chronic failure to plan capacity. To be cutting back on train and station staffing against this background is a lethal gamble with passenger safety."