Thousands of mourners were warned they would miss the Queen’s funeral due to rail disruption.
All lines between Paddington in west London and Reading in Berkshire have been blocked since around 6.30am because of damage to overhead electric wires, Network Rail said.
Services run by GWR, Heathrow Express and the Elizabeth line are expected to be disrupted for the rest of the day.
All public viewing areas for the Queen’s funeral procession are full, London’s City Hall said.
Passengers on a GWR train due to run to Paddington were told by a member of staff using the public address system: ‘My sincerest apologies for the delays on such an important day for the country.’
Mourners travelling to the funeral events in Windsor from Paddington are also affected.
Some passengers trying to travel into London from the West Country faced delays of more than two hours in their journey, meaning they would miss the start of the funeral.
Several said they would watch the service on their phones while en route.
Bev Palfreman said she was ‘absolutely gutted’ train disruption meant she would miss the start of the funeral.
The 61-year-old from Okehampton had been travelling from her home to Paddington station but when the service was cancelled at Reading she had to board a train to Waterloo instead.
She said: ‘The Queen has just been there throughout the whole of my life. This was the only thing I wanted to do.’
Although she will miss the service, Ms Palfreman is still hoping to meet friends and find a space to watch part of the procession afterwards.
One person wrote on Twitter: ‘I’m stuck on the train for two hours. Got up at 4am to get to Windsor early for the viewing. Absolutely horrible service.
‘Barely even caught this train because nobody at Paddington knew which one it was. Sure didn’t expect this dismal service.’
Affected passengers intending to travel to London are advised to use South Western Railway services from Reading to Waterloo.
The Queen’s funeral begins at 11am at Westminster Abbey, but central London viewing areas for the procession have been closed to avoid overcrowding.
National Rail Enquiries encouraged members of the public who had travelled to London to go to pubs and cafes afterwards to ease the strain on train services, despite many being closed.
A post on Twitter from the rail network’s account read: ‘Cafes, pubs and other hospitality providers around London are expected to be open this afternoon, so please don’t rush home immediately following the state funeral and final procession so you can continue marking this historic day and help ease pressure on the rail network.’
A train which departed Paddington at 6.25am has been stuck outside the station for more than two-and-a-half hours with passengers on board.
GWR told concerned customers that the train is ‘due to be evacuated’.
A Network Rail spokesman said: ‘We are very sorry for the disruption which we expect to continue throughout the day.
‘We are working hard to get services running as soon as possible and passengers are strongly advised to check before they travel.
‘We will continue to update passengers as the situation develops.’
After staff at Paddington told waiting passengers there would be no services from the station today, one person remarked: ‘It couldn’t have happened on a worse day.’
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.
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.
She said: ‘It’s annoying but I’d rather stay calm and sit here and do some knitting.’
Heathrow Airport had previously urged airline passengers to use rail or Tube services on Monday due to road closures in the Windsor area.
The issues come during one of the UK’s biggest transport operations as mourners descend on London and Windsor.
Around 250 extra train services were planned for Monday.
They included a 3am departure from Penzance, Cornwall, for Paddington, which left with no passengers, according to news website CornwallLive.
The service only ran as far as Reading due to the electric wires damage.
Transport for London recorded 2.08 million Tube journeys on Sunday.
That was up 16% on the same day a week earlier and was slightly above pre-coronavirus levels .