The issues include the use of temporary workers, the closing of 40 station ticket offices and rules calling for lone workers to staff some stations. The RMT (Rail, Maritime and Transport Union & TSSA (the Transport Salaried Staffs' Association) said said they may ask members to vote on a strike if LU don't agree to schedule negotiations to resolve the issues.
RMT leader Bob Crow said "Each of these issues is serious in its own right, but together they amount to a fundamental and unacceptable attack on staffing across the network,"
In the same statement TSSA general secretary Gerry Doherty said: "Tube users should be as appalled as our members at the amount of safety issues outstanding, and I hope they will understand that LUL's refusal to discuss these issues in the round left us with no choice but to tell the company that we are now in dispute,".
According to Bloomberg London Underground said the disagreement can be resolved through the 'normal negotiating process,'. "That process has not broken down and it would be totally unreasonable to curtail it by threats of strike action," an LU spokesperson said.
I'm sure more news will develop throughout the day as more new sources get statements from the unions and London Underground.