More than 100,000 London-bound rail commuters - a fifth of the overall total - have to stand at the busiest times of the morning rush-hour, according to Government figures.
Passengers on some morning and evening peak services are travelling on trains which are 60% over capacity on certain routes, the Department for Transport (DfT) figures showed.
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The Cobra committee brings together government ministers with senior officials of the emergency services and security agencies.