Tube strikes are set to go ahead next week after the RMT accused Transport for London of failing to engage in negotiations.
The union is pressing ahead with a further two rounds of 24-hour walkouts, beginning at 12pm on Tuesday, May 19 and again on Thursday, May 21, with the effects spilling across four working days.
Crisis talks were planned for this week, but it is understood no meeting to directly discuss the industrial action was set up.
TfL accused the union of “planning this strike action despite our best efforts to resolve this dispute”.
But an RMT spokesperson said: “Despite promises of talks, TfL has not made any attempt to engage in negotiation meetings to resolve this dispute.
“London Underground is still pushing implementation plans through a forum that excludes senior managers and union officials, instead of engaging in proper negotiations.
“Our strike action remains on as we continue to seek a negotiated settlement.”
The fresh walk outs follow industrial action in April over the introduction of a four-day working week with longer hours, which the union says could increase fatigue and compromise safety.
Under TfL proposals, which the operator insists are voluntary, the working week for most drivers would be cut from 36 to 35 hours over four days, but contractual hours would not change due to the introduction of paid meal breaks.
The RMT is demanding a 32-hour, four-day week instead.
But Aslef, the union that represents the majority of London Underground drivers, has accepted the plan and is not planning strike action.
Mayor of London Sir Sadiq Khan told the Standard earlier this week: “My message to the RMT and TfL is to sort it out.
“Get around the table, resolve these things amicably. The only way you’re going to resolve this is by talking, not by going on strike.”
Claire Mann, TfL's Chief Operating Officer, said: “It is disappointing that the RMT is planning this strike action despite our best efforts to resolve this dispute.
“We have been clear that our proposals for a four-day week are designed to improve work-life balance and are entirely voluntary.
“Any Tube driver who doesn’t wish to opt in to the new, four-day working pattern and associated changes to working arrangements can remain on a five-day working pattern.
“We have also said many times in discussions that we believe the majority of the issues that have been raised would be resolved with more detailed work.
“A significant number of drivers have indicated that they want us to progress plans for the pilot of this new working pattern on the Bakerloo line, and it would deliver benefits both for our colleagues and our customers.
“We urge the RMT to work with us so we can resolve this dispute. In the meantime, we are asking customers to check before they travel and allow plenty of extra time for their journeys.”
TfL said the Elizabeth line, DLR, London Overground, buses, and Trams will be running as normal during the strikes action.
However, the services are expected to be busier than normal as Tube passengers seek alternative routes.
