IT is “only a matter of time” before serious flooding strikes at 57 stations on the London Underground, according to a report.

Kings Cross, Waterloo and London Bridge could be at risk of becoming submerged as heavy rainfall could affect the network.

The stations in the top ten of highest risk include Finsbury Park, Notting Hill Gate, Seven Sisters, Colliers Wood, Stockwell and Marble Arch.

The report, produced by London Underground and obtained by the national press, was commissioned in the wake of Hurricane Sandy which swamped the subway in New York City in 2012.

It says the risk is rising due to climate change and it addresses concerns about how London will deal with the impacts on global warning.

The closures and delays would result in multimillion-pound losses for the tube and the wider economy.

The report says says: “London has been fortunate to escape the worst of recent storm events in the UK, but it is only a matter of time before heavy rainfall seriously affects London and the underground network.

“The risk is generally expected to increase, as climate change predictions are that storms will become more intense. There is some evidence to show that these have already increased in frequency.”

In 2012, the Central line was closed for 26 hours after 3m litres of water went gushing down a ventilation shaft between Mile End and Stratford.

The network has requested £3m over the next three years to analyse the riskiest sites and install preventative measures, but there are concerns this will “not scratch the surface” of it.

But the money given will depend on who is elected Mayor of London in May, as they will also be the chairman of TfL.

The London tube network is one of the busiest in the world, with more than 3.5m passenger journeys a day between 270 stations across the city George McInulty, LU’s programme director for renewals, told the national Guardian: “We are investigating what more we can do to minimise any potential disruption flooding causes to our customers.”