Unions are set to name strike dates on the London Underground today after talks with administrators broke down yesterday.
The series of 24-hour strikes by nearly 1,400 workers was approved by members of the National Rail, Maritime and Transport Workers (RMT), the Transport Salaried Staffs' Association (TSSA) and Unite unions.
They voted 1,369 to 70 this week to strike to protect jobs and conditions threatened by London Underground maintenance firm Metronet's collapse.
RMT general secretary Bob Crow said the strike action had been approved "by an overwhelming margin to take action to protect their jobs, conditions and pensions". Details of the strike are expected to be announced today.
Metronet initiated administration proceedings last month after running an estimated £2 billion over budget to fund its sub-surface lines and Bakerloo, Central and Victoria line contracts.
Workers are currently undertaking maintenance and repair work on nine London Underground lines including the Circle, Victoria and Central lines.
A Transport for London spokesman said. "Our priority is to get Metronet out of administration and a strike will not help that process."