Rail lines between Reading and Newbury are also closed due to a person being hit by a train.

This is causing GWR trains to be diverted, delaying more journeys to the capital.

Elizabeth Abayomi, 18, had been at Paddington since 5am hoping to catch the 6.37am to Exeter to start university.

READ MORE: Mourners to miss Queen's funeral as Reading to Paddington trains blocked

The student, who will study law, said: “We were on the train for a long time then we were told that there had been a fatality at Newbury. The driver recommended that we go and get breakfast and when we got back the train was locked.”

Another passenger travelling to Newport, who did not wish to give her name, had been waiting since 6.40am.

READ MORE: Live updates from the Queen's funeral as mourners blocked by train faults

She said: “It’s annoying but I’d rather stay calm and sit here and do some knitting.”

The issues come during one of the UK’s biggest transport operations as mourners descend on London and Windsor.

National Rail Enquiries is showing that all services to and from the station are “delayed”.

Heathrow Airport had previously urged airline passengers to use rail or Tube services on Monday due to road closures in the Windsor area.