A train company is to scrap first class compartments from most of its trains to create more room for standard class passengers.
Greater Anglia announced the policy will come into effect on January 2 2020.
The firm is replacing all its trains with new, longer versions from the middle of next year.
Only the new intercity trains – which run between Norwich, Ipswich, Colchester and London – will have first class seating.
All other trains on commuter and regional routes will be fully standard class.
Greater Anglia’s commercial and customer services director Martin Moran said: “With the combination of withdrawing first class and our new longer trains, we can provide about 20% more standard seats across our network, which will reduce overcrowding and improve our customers’ experience of travelling with us.
“After listening to customer feedback, assessing the ongoing increases in passenger numbers and taking account of the rail network capacity, we’re taking this step to give the majority of our customers a much-improved service and advising everyone well in advance of the date from which the new policy will apply.”
The operator has written to all first class annual season ticket holders to inform them about the plan, with details of how to swap a first class ticket for a standard ticket towards the end of next year.
The new trains will feature more seats, USB and plug points, air conditioning and free wi-fi.
Department for Transport figures show almost 170,000 passengers were forced to stand during the morning peak in 14 cities in England and Wales last year, which is equivalent to one in five passengers.
Transport Secretary Chris Grayling has previously called for first class to be scrapped on commuter routes to ease overcrowding.