Workers from two of the UK's biggest rail operators, First Capital Connect and National Express East Anglia, will walk out on Monday 30 March in protest against job losses.
About 1,500 staff members are expected to join the 24-hour strike, which is expected to disrupt the operator's commuter services into London.
The Rail, Maritime and Transport union (RMT) has ordered the strikes, saying that the mayor's proposal to cut 300 jobs was solely to maintain profits and dividends, despite the operators recording significant profits in 2008.
The RMT believes that the cuts will lead to reduced services and the creeping casualisation of professional railway jobs with the use of agency and contract labour.
The RMT is, however, one of four rail unions recognised by First Capital Connect, which means that the majority of staff will still be available for work.
The strikes coincide with conductors striking at London Midland over Sunday working.
By Daniel Garrun.