The capital is braced for travel woe as the boss of London Underground (LU) said he is not hopeful that next week’s 48-hour walkout will be called off.
Members of the Rail, Maritime and Transport Union (RMT) will stage a strike on the evening of Monday 28 April, and again a week later for three days, in response to the Government’s plans to revolutionise the London Underground's ticketing service, which will incorporate the shutting down of ticket offices and the loss of 950 jobs.
The RMT and LU have been engaged in talks at Acas, the Advisory, Conciliation and Arbitration Service, but have so far been unable to broker a deal.
The LU said it had made concessions but the union had refused to back down from the planned strike action.
LU's managing director Mike Brown told the BBC: “At the moment I am not optimistic because they (RMT negotiators) have given no signs of responding to the fact that we have amended the proposals.
"Our staff are going to get quite rightly a very good deal in all this."
The RMT has confirmed the strike will begin at 9pm on Monday 28 April until the same time on Wednesday 30 April.
A further strike is planned for the following week from 9pm on Monday 5 May until the same time on Thursday 8 May.
Widespread disruption was triggered in February when a 48-hour walkout left millions of commuters facing long delays and cramped condions.
Following further talks after this action, the RMT sent a letter to its members saying that the LU had said it would conduct a station-by-station review of the ticket office closures, which might allow some to remain open.
However, Mr Brown told the BBC that all ticket offices would be shut when the changes are implemented - but he added that visitor information centres in large stations would also sell tickets.
In an open letter to the public on Tuesday, Mr Brown said: "Our proposals mean radically improved customer service while allowing us to bear down on the cost of transport fares. We will be emulating the levels of face-to face customer service we gave during the 2012 Games, with more staff available in the public areas of stations to help and advise passengers and keep everyone safe.
"Ticket offices do not control the safety and security of stations. Station supervisors and dedicated controls rooms do that, and this will continue.
"Every station will remain staffed and controlled at all times, and new ticket machines, contactless payment and a 24 hour service at weekends will further improve life for our customers."