Some of the worst levels of overcrowding on train services are faced by rail passengers travelling to London Waterloo.
The most crushing period is during morning peak hours where hundreds of trains are found with commuters huddled together.
Last year, 98% of train services arriving into Waterloo between 8am and 9am had passengers forced to stand, according to data from the Department for Transport (DfT).
This means around 20,000 passengers a day were left on their feet during the morning rush hour – 39% of the total.
In addition to this more than a third of services coming into Waterloo during the one-hour period were above capacity, carrying more passengers than the trains are designed to allow.
South West Trains , the main rail operator at Waterloo Station said it is constantly working on new ways to alleviate pressure on passengers and its train services.
A spokesperson for South West Trains said: "The majority of our peak time services are already formed of 12 carriages - the longest possible train that can run on our network.
“However, we are far from complacent and are continuing to invest to provide additional capacity where it is possible.
"More than £800million is now being invested to provide even more space for passengers. This includes creating a bigger and better London Waterloo and introducing a fleet of 150 brand new carriages.
"By the end of 2018 we will be providing 30% more space for passengers during the busiest times of the day.
"This work will also unlock London Waterloo and the network to allow further investment to increase capacity and improve journeys for longer distance mainline services."
This year SWT has introduced 108 additional carriages; providing extra room on 77 morning and evening services across its network.
The DfT figures also revealed the worst trains for overcrowding in London were those arriving in Moorgate, where 100% of all services between 8-9am are over capacity, with 44% of all passengers standing.
Public transport campaigner, Lianna Etkind, at Campaign for Better Transport said: "Rail passengers are paying record amounts for their tickets and it's not acceptable that so many regularly have to stand.
“They have every right to be outraged at the levels of overcrowding - levels which have persisted on some routes for many years.
"In the next few years, revenue from tickets will exceed the cost of running the railways. The millions who rely on the trains want a commitment from the Government that there will be long term investment in rail capacity.
She added: “Train companies and Government need to prioritise investing in new rolling stock, and investing in infrastructure like longer platforms, so that longer carriages and more frequent trains can be rolled out onto the network.
"We also need to reduce the pressure on rush hour services, which are often the busiest.
"The Government must honour its promise to introduce season ticket discounts for part time workers to help tackle overcrowding, and make rail travel more affordable, too."