PASSENGERS are being warned to expect delays on the rail network over the next week due to leaves on the lines.

Rail operators have issued a warning to commuters that all services could be delayed by up to 10-15 minutes due to “leaf fall”.

Autumn is traditionally a difficult time for railways across the country, bringing wet weather and leaf fall which creates mulch that sticks to the track and gets compressed and hardened by train wheels into what was described as a 'Teflon-like' layer.

This causes the track to be as slippery as black ice, so train wheels lose grip and in some cases become damaged.

The mulch can also cause the electrical circuits on the tracks to fail, which can also cause delays.

A spokesman for Network Rail said: "Managing the vegetation which grows on the railway is an important way to mitigate the problems caused by leaf fall. 

"We focus our resources to keep the railway safe and running. This includes keeping the area between the track rails completely clear and removing any lineside vegetation situated on our land that poses a threat to the safe running of the railway or our operations."

Southern Railway chief executive Charles Horton said: "Challenging conditions during the autumn mean train services across the country become vulnerable to poor weather and slippery rails, compromising performance and certainty for passengers".

"We, like other train operators in the UK, are taking steps to reduce the risk of disruption during the period."

South West Trains said the problems can affect train punctuality.

A statement said: "While we attempt to ensure that peak hour trains are not affected, this is not always possible especially when we have a high number of carriages affected by wheel flats."