Train drivers with Southern have voted to go on strike in a row over pay.
Members of Aslef backed walkouts by 91 per cent and other forms of industrial action by 95 per cent.
The turnout was 85.3 per cent.
The votes, and the turnout, were both well above a threshold being planned by the government for union strike ballots.
Aslef said it is meeting the company tomorrow for talks to try to resolve the dispute.
Southern services were disrupted today after a signal problem at Haywards Heath in West Sussex led to hold-ups of up to one hour between London and the Sussex coast.
A number of trains were cancelled, with passengers packing into the trains that were still running.
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