Talks will be held today to help resolve a long-running dispute over the role of guards on Southern Rail.

Leaders of the Rail, Maritime and Transport (RMT) union will meet company officials under the chairmanship of the service, Acas.

RMT members have taken almost 30 days of strike action since the dispute began almost a year ago.

These talks are happening just days before the drivers' union Aslef announces the result of a ballot of members on a proposed deal to end a separate row over driver-only trains.

Aslef leaders are recommending the agreement for acceptance.

The RMT have said new figures showed that the equivalent of 1,000 services a year continue to operate without a second member of staff, despite promises made by bosses of Southern's owners Govia Thameslink Railway.

The RMT said that in January, there were at least six times more Southern services travelling without a second member of staff than was promised.

At the time the company faced industrial action including a ban on overtime by drivers which led to delays and cancellations.

The union said the new figures provided by rail workers and passengers from January 20 to February 6, when there was not any industrial action, showed that at least 26 trains did not have a scheduled on board supervisor - an average of three services a day or 1,000 a year.

Mick Cash, the RMT general secretary, said: "These figures confirm that as a bare minimum the equivalent of 1,000 services will no longer have a second member of staff in addition to the driver.

"That's 1,000 journeys where a disabled passenger may not be able to get on or off the train or where passengers and the driver are at increased risk from anti-social behaviour or if something goes wrong, such as a derailment or fire.

"These are only the instances that have been reported and I have to say that our members think these figures are the thin end of the wedge and instances of driver-only trains are far more widespread and increasing.

"Guaranteeing a second member of safety critical staff on every train is the only way you can guarantee access for all and a safer journey for passengers."

A Southern spokesman said: "We said we would roster a second person to every train that has one today, and we are.

"However, we also said in exceptional circumstances when an on board supervisor is unavailable we will run the train as it is passengers' interests to do so."