Mayor of London Boris Johnson has outlined the infrastructure improvements needed to ensure the capital remains among the world's top cities.

Mr Johnson issued a "wake-up call" as he launched a consultation on his 2050 London Infrastructure Plan yesterday (July 30th), which details the investment needed to keep pace with a rapidly expanding population.

According to the mayor, the total amount of funding required by the capital's infrastructure over the period could reach £1.3 trillion.

One of the items on the mayor's wish list is an inner orbital road tunnel, which could reduce traffic congestion. Improvements to London's rail network could double capacity, while a new, four-runway airport is needed in the Thames Estuary.

Mr Johnson said: "Infrastructure underpins everything we do and we all use it every day. Without a long term plan for investment and the political will to implement it this city will falter."

The consultation will run for three months, and a final report is expected to be published in early 2015.