Campaign to save London Tube ticket offices
A campaign has been launched to turn London's council elections in May into a referendum on plans to close all Tube ticket offices by 2015.
Labour and the Transport Salaried Staffs Association (TSSA) said it would make stations unsafe and are urging voters to "save their ticket office".
Mayor of London Boris Johnson made the announcement in November.
He said the plan meant more staff would be present in ticket halls and safety would not be compromised.
The campaign was launched earlier at London Bridge station with the first of 500,000 campaign leaflets handed out to commuters.
TSSA leader Manuel Cortes said: "This is a real chance for Londoners to send a message to Mayor Boris Johnson telling him what they really think about his U-turn on his 2008 election pledge to keep open every ticket office.
"We say a closed ticket office makes a station less safe and secure to the travelling public. They will have to tell voters why they believe the complete opposite."
Transport for London said following the introduction of Oyster cards only about 3% of people used ticket offices.
Phil Hufton, of London Underground, said: "In future, more staff will be visible in our ticket halls where they can help customers to buy the most appropriate ticket for their journeys and all stations will continue to be staffed at all times whilst services are running.
"Statements about stations becoming less safe are completely unfounded."