Last ditch talks aimed at averting strikes by London Underground workers in a row over ticket office closures, will be held tomorrow, with time running out for a deal to be agreed.
Members of the Rail, Maritime and Transport union (RMT) and the Transport Salaried Staffs Association are due to walk out for 48 hours from 9pm on Tuesday, and again a week later in protest at the closures, and the loss of hundreds of jobs.
London Mayor Boris Johnson has offered to hold talks, but only if the industrial action is called off.
The two sides met at the conciliation service Acas last week, with little sign of a breakthrough.
Bob Crow, general secretary of the RMT, said: "The Acas talks reconvene tomorrow and RMT remains totally committed to making progress through those negotiations.
"In the meantime I have had further correspondence with Boris Johnson and we are available for direct talks with the Mayor with no preconditions.
"We are awaiting his confirmation that be is up for getting round the table with no preconditions or caveats."
London Underground has announced contingency plans for the strike days, but passengers face travel chaos if the action goes ahead.