Firefighters are to stage two eight-hour strikes in the capital in a row over new contracts, it was announced today.
Members of the Fire Brigades Union in London will walk out from 10am on October 23 and November 1 after voting by 79% in favour of a campaign of strikes.
The union had given London Fire Brigade until today to withdraw letters it said effectively sacked firefighters, to be re-employed on worse terms.
FBU general secretary Matt Wrack said: "Firefighters hate going on strike, but they hate being bullied even more. The London Fire Brigade needs to lift the sacking notices and start negotiating properly."
London firefighters have been taking action short of a strike, including an overtime ban, since last month.
The fire brigade is proposing to change the start and finish times of duty for its frontline firefighters by reducing the current 15-hour night shift to 12 hours, and increasing the current nine-hour day shift to 12 hours, providing a longer day shift.
The brigade insists firefighters will continue to work two day shifts followed by two night shifts and then have four days off.
A spokesman said: "The current start and finish times have been in place since 1979 and the work we do today has changed dramatically.
"We don't just respond to fires any more. Firefighters train for and attend a much wider range of incidents such as flooding, collapsed buildings, chemical incidents etc, and work harder than ever before to prevent fires from happening in the first place.
"The current start and finish times also result in a change of shift during both the morning and evening rush-hours when fire brigade incident demand is at its highest.
"The changes would significantly increase the productive time available during the day shift for essential training and community fire safety work to be arranged. For instance, firefighters now prevent fires by visiting Londoners in their homes, fitting free smoke alarms and offering advice on preventing fires.
"The new start and finish times would also mean less disruption to services during a crucially busy period of the day. The current shift change takes place during morning and evening rush-hour."
The brigade has drawn up contingency plans for dealing with a strike, adding that it can no longer rely on support from the military with their green goddesses as happened in previous disputes.
The authority entered into a five-year, £9 million contract in June 2009 with AssetCo to provide London with a contingency level of fire and rescue services during any industrial action, natural disaster, severe pandemic illness or catastrophic incident.
The arrangement in place involved the deployment of up to 27 fire appliances.
"We believe that the service will provide, so far as is reasonably practicable, an acceptable level of contingency cover," said the brigade.
In previous disputes, fire brigades drafted in the military, using army Green Goddess vehicles, to cover for striking firefighters, but the Government announced in 2006 that military support was removed.
Brian Coleman, chairman of the London Fire and Emergency Planning Authority, said: "Firefighters are going to be striking over plans to reduce a 15-hour night shift by three hours, and add those three hours to a nine-hour day shift.
"That is all these proposals seek to do, no station closures, no increase in hours and no change to the four-day rest period between shifts. This is about making more time in the day for vital training and fire prevention work.
"We've been discussing this for five years and have offered to compromise, so it's time for the FBU to stop blocking these changes."
Mr Wrack added that the union is "ready to talk, but not to be bullied", adding: "Lift the sackings now and there will be no strike in London."
He said there had been no response from London Fire Brigade to the deadline set by the union, which is why strike dates were set.