Image caption The BBC understands soldiers could be asked to drive buses carrying Southern rail passengers

Soldiers are on stand-by ready to drive rail replacement buses during Southern rail strikes, the BBC has learned.

BBC South East understands the Army has been asked to put contingency plans in place to ensure commuters get to work if the disruption continues.

Military leave could be cancelled and soldiers asked to drive buses carrying passengers in the worst hit areas.

The Ministry of Defence said it had no plans to deploy military personnel in response to the strikes.

Paul Cox, of the RMT union, said there was "no need" to call in soldiers.

"It's ridiculous to use the Army when the government could easily settle the dispute," he said.

The ongoing dispute between Southern and the RMT and Aslef unions over driver-only-operated trains started in April, leading to the worst disruption on the railways for 20 years and affecting hundreds of thousands of commuters.

If the Army is drafted in to help out, it would be reminiscent of the firefighters' strike 14 years ago when Army personnel operated Green Goddess appliances.

Image caption Army personnel operated Green Goddess appliances during the firefighters' strike 14 years ago

Figures published by the Mayor of London on Thursday revealed 57% of trains on Southern's Mainline and Coast line arrived at their destination on time in the five weeks to 10 December.

The figures also showed 62% of trains across all Govia's franchises, which include Govia Thameslink train services and the Gatwick Express, arrived at their destination on time in the same five weeks.

Three further strike days are planned at the end of this month, and six during the second week of January.

Paul Maynard, the Parliamentary Under Secretary of State at the Department for Transport said the government was "closely liaising with the Confederation of Passenger Transport to see how bus and coach operators could assist with providing alternative transport".

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Planned Southern strike dates

00:01 Saturday 31 December to 23:59 Monday 2 January (RMT conductors' strike)

00:01 Monday 9 January to 23:59: Saturday 14 January (Aslef and RMT drivers' strike)