The bitter dispute over the role of conductors on Southern Railway could be resolved for a fraction of the £20 million announced by the Government to improve services, it has been claimed.

The Rail, Maritime and Transport (RMT) union said less than £1 million of the "Government bailout" could be used to settle the long-running row.

Union members were on strike again on Wednesday, causing fresh travel misery for hundreds of thousands of passengers.

The RMT said it had calculated that simply filling 20 guard posts which were effectively "deleted" by the company in January would guarantee a second safety-critical person on the trains, the issue at the heart of the dispute, and would dramatically improve the reliability of services.

The union estimated that the total cost would be "comfortably less" than £1 million.

RMT general Secretary Mick Cash said: "The key issue at the heart of the dispute is that GTR (Southern's owners) have refused to agree that passengers will keep the guarantee they currently have of a safety critical conductor/on-board service supervisor staff on their train in addition to the driver.

"The company say this is because, in the event of the conductor OBS not being available, they have to cancel trains.

"However, the key plank of Southern's argument is in fact a lie - non-availability of conductors as a cause of train cancellations is almost statistically irrelevant, accounting for 0.06% of cancellations, according to information provided the company to MPs.

"That equates to less than one train a day, whereas the Southern mismanagement of the franchise accounts for hundreds of cancellations.

"The cost of staffing up to a level that would meet the safety guarantees, improve dramatically the level of passenger service and resolve the dispute would be a faction of the cash Transport Secretary Chris Grayling has thrown at Southern and the profits being stockpiled by Govia."

Mr Cash said the RMT wanted urgent talks around these issues to find a solution to the dispute.

The latest strike will end at midnight but more walkouts are planned for next month and in the run-up to Christmas as well as over the New Year.

A Southern spokesman said: "We offered the RMT a guarantee around numbers of on-board supervisors and indeed we are already recruiting an additional 100 people into this role.

"The sticking point isn't the number of staff, it is the RMT's determination to hang on to its union muscle by insisting a train could never leave without an OBS even if that means stranding hundreds of passengers.

"This isn't about money this is about muscle."

The RMT said the second day of strike action was being "solidly supported", with picket lines mounted outside stations in London and Sussex.

Mr Cash added: "RMT thanks the travelling public for their continued support and understanding on the second day of the latest phase of strike action. The response this morning has been fantastic.

"This strike is all about safety and, despite the lies and dirty tricks from Southern, that message is ringing through loud and clear.

"Passengers know that Southern/GTR is a basket case rail company that has chosen to declare war on its customers and staff alike.

"They are a disgrace and the fact that Chris Grayling and his Government continue to let them off the hook is a national scandal."