Rail passengers travelling to and from London were today facing misery as flooding and strong winds cause delays on the railways.
Fewer than half the normal number of services were running on some major commuter routes to London from the Home Counties this morning.
Speed restrictions have also been put in place across large parts of the country as strong winds batter Britain.
Network Rail's Robin Gisby said: "I'm afraid it's going to be another difficult day for passengers."
Mr Gisby, the managing director of network operations, told BBC Radio 4's Today programme: "We have got restrictions at Maidenhead - that's groundwater coming up into the railway as much as flooding coming sideways.
"We're only running five trains an hour - normally It would be 12 through there - and there are delays of five, 10, 15 minutes a train.
"Similarly we have got a restricted service between Oxford and down to Didcot. We don't expect that to get any worse today - obviously we will keep passengers updated through the websites and so on.
"With the rain that's coming tonight and the effect that has on the Thames, we will keep watching that over the next couple of days."
Among the worst-hit sections of railway affecting London were:
First Great Western trains from London Paddington to Swindon and Swansea;
Southern trains from East Croydon to Oxted;
South West Trains services from Staines to Windsor and Eton Riverside - no service;
South West Trains from Portsmouth Harbour to London Waterloo;
First Great Westerm Services from Penzance to London Paddington.
Mr Gisby, who has warned it could take months before the rail network is fully repaired following the floods, said Network Rail was watching "several hundred sites" and there were concerns about embankments, including on the Somerset Levels where they were being battered by waves from an "inland sea".
He said Network Rail was spending around £10 million a week on earthworks: "That's money that's very necessary because we have to take the Victorian inheritance we have got and build it for the very different climatic conditions we are clearly going to face in the future."
Floods in pictures
