Tube drivers are to vote on industrial action in a row about working conditions.
The announcement has come as Conservatives on the London Assembly called for curbs on strikes on the Underground.
The union organising the ballot called that an attack on fundamental rights.
Rags Martel reports.
More top news
The former Tottenham and Arsenal player made his feelings clear after visiting the Cambridge Street Cafe in south London.
Donna Stringer is in intensive care with her family by her side two weeks after the horrific arson attack in east London.
Demonstrators have blockaded the entrance tunnel to Heathrow Airport in apparent protest at plans to build a third runway.