Commuters are being urged to only travel if necessary during the latest round of train strikes on Wednesday.
Around 40,000 members of the RMT union working at Network Rail and 14 train operating companies will walk out in a dispute over pay and working conditions.
Only around 20 percent of train services are expected to run.
While TfL services are not part of the strike some, including the new Elizabeth Line and London Overground, could be disrupted as a knock-on effect of striking Network Rail signallers.
London Overground will run a reduced service between 7.30am and 6.30pm only, with no service in several areas such as between Romford and Upminster or Kilburn High Road and Euston.
The Elizabeth line will run a reduced section, with trains on its eastern leg not stopping at Goodmayes, Forest Gate, Manor Park and Maryland.
TfL also said there would be no service between Queen's Park and Harrow & Wealdstone on the Bakerloo and disruption on the District between Parsons Green and Wimbledon, and Turnham Green and Richmond.
The latest action comes after the biggest rail strike in three decades took place over three days last month.
Network Rail urged passengers to check ahead of time with a special timetable running Wednesday between 7.30am and 6.30pm.
Its chief executive, Andrew Haines, called the strike “pointless” and criticised the RMT union as being “hell-bent” on “political campaigning”.
Mr Haines said: “Despite our best efforts to find a breakthrough, I’m afraid there will be more disruption for passengers this week as the RMT seems hell-bent on continuing their political campaigning, rather than compromising and agreeing a deal for their members.
“I can only apologise for the impact this pointless strike will have on passengers, especially those travelling for holidays or attending events such as the UEFA Women’s Euro 2022 semi-final (Wednesday 27th) and the opening ceremony of the Commonwealth Games (Thursday 28th).
“It is frustrating to yet again ask our passengers to change their plans and only make essential journeys.”
However, Mick Lynch, the RMT’s General Secretary, said a strike was only going ahead because there had been no breakthrough in talks, and the union would continue dialogue.
He told BBC Radio 4’s Today Programme: “If we could get a breakthrough then we wouldn't have to take strike action but there's a big gap between the parties at the moment.
“So I'm not going to raise false hopes but we are constantly in dialogue with all of the elements of the industry."
The union said it would be operating picket lines at several key London stations throughout Wednesday including Liverpool Street, Euston and King’s Cross.
The train operating companies affected by the strike are: Chiltern Railways, CrossCountry Trains, Greater Anglia, LNER, East Midlands Railway, c2c, Great Western Railway, Northern Trains, South Eastern, South Western Railway, TransPennine Express, Avanti West Coast, West Midlands Trains and Govia Thameslink Railway.
A separate strike by members of the Aslef union is set to take place on Saturday across Arriva Rail London, Greater Anglia, Great Western, Hull Trains, LNER, Southeastern and West Midlands Trains.
