RAIL services at two train operators will be hit by a fresh guards' strike on Saturday, causing more disruption for passengers.

Members of the Rail, Maritime and Transport union on South Western Railway (SWR) and Arriva Rail North (Northern) will walk out for 24 hours, leading to the cancellation of hundreds of services, with buses replacing some trains.

The strike on SWR is the fourth consecutive Saturday stoppage, with no sign of a breakthrough to the long-running row over driver-controlled trains.

The Northern strike is going ahead even though the two sides are meeting for talks next week at the conciliation services Acas.

RMT general secretary Mick Cash said: "The Northern Rail action goes ahead as planned in the guards safety dispute as at this stage the company have offered us nothing of substance that would allow our executive to consider suspension.

"RMT will be taking part in talks through Acas next week but we have been through this process on numerous occasions now and we need something concrete from the company around the fundamental issue of the guard guarantee to allow us to make some serious progress.

"The issue at the heart of the dispute remains the same - a safe, accessible and secure railway for all and we thank the travelling public for their continued support for RMT's campaign."

On the SWR dispute, Mr Cash said: "There's a simple solution to this dispute and it means SWR stop playing with words and negotiate the guard guarantee that reflects the best safety practice elsewhere in the industry.

"SWR want to create a loophole that would allow them to operate driver only at will. If they close that off there's a deal waiting to be done and I would ask them to get round the table with us and bolt it down as a matter of urgency."

An SWR spokesman said: "We thank all of our customers for their patience and those guards who have worked to keep services moving during the RMT's unnecessary summer strikes.

"We know how frustrating the RMT's industrial action is for customers, and we are doing everything we can to minimise disruption, maximising service provision and extending trains where possible to provide additional seats.

"We continue to seek constructive talks with the RMT and have proposed a framework for these talks which would guarantee a second person with safety critical competencies rostered on all trains."

A Northern statement added: "We expect to run around 30% of services and all customers are advised to plan carefully if they intend to travel on the rail network.

"Unfortunately, on some routes, we aren't able to run services, while others have a limited service. On those routes where we are able to operate trains, we expect all services to be extremely busy. We also have replacement bus services available on some routes where trains aren't running."

Engineering work will also affect services on both operators on Saturday.