Seven people were injured in the Camden crash

The Rail, Maritime and Transport (RMT) union voted by 55% in favour of strikes.

It is part of a row over safety on London Underground (LU), following two derailments in October.

The action will probably start within 14 days with a series of 'go-slows' but LU said it will "change nothing".

Union members will be told to drive at just 10 or 15mph instead of the normal 40-45mph over lines where they have safety concerns.

The RMT union's General Secretary Bob Crow said the action would throw the network into "chaos".

It will only cause disruption to Londoners and Tube users travelling to work, or Christmas shopping for their friends and families LU Managing Director, Tim O'Toole

He said: "We regret the disruption that this will inevitably cause Tube users but we hope they will continue to show understanding that these actions are being taken for safety reasons and continue to support our aim for a safer Underground network."

Thursday's ballot result also showed that 81% of members voted to take industrial action short of strikes.

RMT's executive will meet next week to decide whether to set a series of strike dates as well as order the go-slow.

Mr Crow said union members employed as station staff will also be told to close stations if they become overcrowded because of the industrial action.

The union is campaigning for safety checks on the Tube every 24 hours and for all maintenance work to be brought back in-house.

'Run Tube safely'

It also published an opinion poll which showed that 80% of the public supported the right of Tube workers to take industrial action over safety.

LU Managing Director, Tim O'Toole said: "A Tube strike or go-slow now changes nothing.

"It will only cause disruption to Londoners and Tube users travelling to work, or Christmas shopping for their friends and families.

"The way forward is for the RMT, all unions and Tube staff to work with me to make sure we can run the Tube safely and efficiently."

London's Tube passengers have already had to cope with one 24-hour strike this month.

Reduced services ran on the Hammersmith and City line, and the Circle line was shut on 14 November as the RMT took action after one of its members was sacked.