Members of the Rail, Maritime and Transport (RMT) union on South West Trains have voted to take industrial action short of a strike in a row over an Olympic bonus, but rejected strikes by a narrow margin of just four votes.
General Secretary Bob Crow said: "Our members have been consulted by the union in this democratic vote and by the narrowest margins have opted not to take strike action but have voted by a significant margin for action short of a strike.
"The position will be considered further by the union's executive."
Workers at South West Trains have confirmed they will take industrial action during the Olympics, as revealed last week on ITV Meridian.
Members of the RMT union on South West Trains have voted to take industrial action short of a strike in a row over an Olympic bonus.