Strike action threatens to disrupt travel to and from London Heathrow this Christmas.
The transport union, RMT, is balloting 400 drivers on the Piccadilly Line over a ‘wholesale breakdown in industrial relations’.
The Piccadilly Line is the fourth busiest on the London Underground network and serves all five terminals at Heathrow.
The ballot will open on November 1 and finish on November 15. Once voted on, the union must give at least seven days’ notice of any strike action.
A spokesman said if the strike goes ahead, he could not rule out action in December, whch could impact the busy Christmas travel period.
Mick Cash, RMT general secretary, said: "Industrial relations on the Piccadilly Line have been corroded through repeated failures to follow agreements, policies and procedures. It is those failures that have led to the wholesale breakdown in industrial relations which has triggered this ballot for action.
"RMT members on London Underground will not stand by while agreed policies that were put in place to maintain tube safety are systematically ignored and undermined
"The union remains available for talks."
