(Sharecast News) - Commuters at the UK's busiest railway station face five days of misery from Tuesday morning, as South Western Railway guards stage a massive strike.The train operating company - the only one serving London Waterloo on the capital's south bank - has been in dispute with members of the Rail, Maritime and Transport Union since it took over the operation from the Stagecoach-owned South West Trains in August last year.South Western Railway is a joint venture, 70% owned by FTSE 250 passenger transport operator FirstGroup, and 30% by Hong Kong-listed rapid transit company MTR Corporation.Nearly a third of services across the SWR network - which stretches from London to Weymouth, with services also reaching Reading, Bristol and Exeter - will be cancelled between Tuesday and Friday.On Saturday, only half of all scheduled services will operate.The dispute stems from claims by the union that the company is not guaranteeing the jobs of its guards - something South Western Railway disputes.It is understood SWR has plans to hire more guards than it currently employs, but it also wants the ability to operate a service with only a driver at times when a guard is unavailable - something the RMT has taken issue with."The RMT is cynically targeting hard-working commuters, families trying to enjoy the half-term holidays and sports fans with its latest strike dates," a spokesperson for SWR said in a statement."We have guaranteed a guard to be rostered on every single service, and our growth plans mean more guards, not fewer."It is time for the union to stop spreading myths and causing misery to our customers and colleagues, and commit to resolving this dispute."SWR said it would do "everything" it can to keep passengers moving, and reduce disruption.RMT general secretary Mick Cash rebutted that, however, saying SWR had stalled talks and failed to provide any sort of offer that came close to resolving the dispute."Our dispute is about safety, security and access on SWR while the company look to open up a loophole that would allow them to run services driver-only at their discretion."Recent figures have shown a shocking surge in violence on our railways."It is, frankly, appalling that SWR are looking for a green light to throw the guard off their trains as and when they see fit in the name of profit."