A surge in passengers means rail providers are bolting on additional carriages to trains on the day of the King’s coronation.

Govia Thameslink Railway (GTR), which operates Gatwick Express, Southern, and Thameslink, said some of its services will have “more carriages than normal” on May 6.

And while there is no planned engineering work affecting lines serving London on coronation day, there could still be delays in the South East as much of the additional passenger demand is expected to come from within the region.

It is not thought that GTR will provide any extra services.

It comes as other rail providers around the country announced they are laying on extra trains, with hundreds of thousands of people expected to travel to London for the occasion.

Great Western Railway said it will run some “very early” additional services to London Paddington from major stations in south Wales, south-west England and the Thames Valley area on May 6.

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It will also operate an “enhanced service” between Windsor and Slough on May 7 and the early hours of May 8 for concertgoers.

South Western Railway said it will run its usual timetable on the day of the coronation service, but there will be additional trains between London Waterloo and Windsor for the coronation concert.

On May 6, Southeastern will run additional trains between Dartford and London Charing Cross, and longer trains on the Maidstone East Line and between London Victoria and Gillingham.

Transport for London said its services may be “very busy” at “key transport interchanges” such as Tube stations around Westminster and those with connections to mainline trains.

Many train companies are not planning to enhance their operations for the weekend as much of the additional passenger demand is expected to come from within the South East.

That means the transport operation will be slimmed down compared with the late Queen’s funeral in September last year, when around 250 extra train services ran, including some overnight.

Major stations in London were kept open overnight to provide shelter for mourners waiting for trains home.

GTR was contacted for comment.