Green city plans: all-night Tubes and a West End car ban

Her transport manifesto also proposes a 20p cut in bus and off-peak Tube fares and a 20mph speed limit on virtually all roads - her "20/20 vision for London".

While Ms Berry has no chance of being elected Mayor, many of her policies have a high chance of being implemented if Ken Livingstone is re-elected on 1 May.

Mr Livingstone already works in tandem with the Greens on the London Assembly and has stated his willingness to give Ms Berry a job in a thirdterm administration.

He previously suggested running the Tube later at weekends but has been unable to implement the 2004 manifesto pledge because of opposition from unions and the knock-on problems it would cause for early shift workers and travellers, especially at Heathrow. Services have to start later the following morning to allow Underground maintenance work to take place.

However Ms Berry believes that the Tube can be kept running by slowing the pace of repairs and diverting cash from car-dependent schemes such as the Thames Gateway Bridge.

She said: "Every Londoner is familiar with the dash for the last Tube home. I want to end the restrictions that the Tube timetable places on our city's nightlife.With an increasingly continental culture, the last train is often well before closing time, and many nightclubs are barely open at midnight.

"By investing in all-night services at weekends, we'll open up London, meaning better nights out and better business. It will also help to relieve closing-time tension on our streets, making life safer."

She plans to cut 20p off fares, meaning a single bus trip would cost 70p for Oyster users. She would shorten bus routes and encourage passengers to switch buses by limiting the cost to £1 for an hour of travel, regardless of the number of buses boarded.

Ms Berry also said she would press ahead with tram schemes in west London - abandoned by the Mayor because of the level of opposition - and between Camden and Peckham.