Piccadilly line Tube drivers balloted in safety row

The Piccadilly line serves 53 stations, including Heathrow Airport terminals

London Underground's Piccadilly line drivers are to vote on industrial action in a row over safety.

The ballot could lead to the closure of the line, the Tube's fourth busiest, which serves Heathrow Airport.

Managers have been accused of the "wholesale abuse of procedures and agreements" and ignoring safety concerns about weak brakes.

But London Underground operations director Pat Hansberry said he was disappointed by the decision.

"We urge the union leadership and members to work with us constructively on the issues they have raised," he said.

The ballot, organised by the National Union of Rail Maritime and Transport Workers (RMT), will close on 20 October.