Londoners have been urged not to travel on the Tube next Tuesday and Wednesday amid widespread industrial action on the network.
Transport for London (TfL) said that strike action would cause severe disruption to all Underground lines.
It comes as some 10,000 Tube workers from the RMT and Unite unions prepare for a second day of strike action this month after shutting down the network on June 6.
Separate industrial action taking place across the UK’s rail network is also expected to cause chaos for commuters. The disputes have flared over pay, jobs and conditions, with the Transport Salaried Staffs Association (TSSA) announcing more strike ballots at rail companies on Wednesday, increasing the threat of a prolonged summer of disruption.
TfL said they expect “severe disruption or no service” on all Underground lines on Tuesday if the strike action goes ahead, with no services running before 8am on Wednesday.
They urged customers to avoid making journeys on Wednesday until mid-morning.
Meanwhile, Londoners seeking to use any Underground services that are running on Tuesday have been urged to complete their journey by 6pm.
Bus services are likely to be “extremely busy” as a result of the strikes, they said.
TfL advised anyone wishing to travel to consider walking or cycling.
Meanwhile, strike action taking place across the UK’s rail network is also expected to disrupt TfL services, including the London Overground.
A reduced services will operate on the London Overground and the newly opened Elizabeth Line on June 21, 23 and 25.
Disruption from the national rail strike will also affect customers on mornings when no strike action is planned, including Wednesday, Friday and Sunday.
RMT strike action is continuing on the Night Tube but TfL said they were running a good service on the Victoria and Jubilee lines, with at least three trains per hour. A regular service is also running on the Central Line with at least two trains per hour.
Andy Lord, TfL’s Chief Operating Officer, said the majority of Tube stations will be closed next week with no services running.
“Alternatives to the Tube are likely to be much busier than usual and we expect the severe disruption caused by this strike to continue into the morning of Wednesday 22 June. I’m very sorry for the impact this will have on people’s journeys,” he said.
“This strike is particularly frustrating as it comes so soon after industrial action earlier this month, no changes have been proposed to pensions and nobody has or will lose their job as a result of the proposals we have set out.
“We’re urging the RMT and Unite to call off this strike and to work with us to find a resolution and avoid the huge disruption this action will cause to people’s journeys and to our economic recovery.”
TfL said they had met RMT and Union officials on Wednesday but were not able to resolve the dispute over pay and pensions.
They denied claims that they would not recruit into between 500 or 600 posts as they become vacant.
The RMT has called for talks with Transport Secretary Grant Shapps and Chancellor Rishi Sunak, with the union’s general secretary Mick Lynch accusing the Treasury of “calling the shots” and not allowing rail employers to reach a negotiated settlement.
Network Rail’s chief executive Andrew Haines denied the claim, saying the Treasury has set a financial framework.
