Mr Hughes launched his mayoral campaign from a London bus

The Liberal Democrat MP launched his manifesto with a desire to make London a safer, more united place.

He plans five free entries to the charge zone a year and would scrap plans for a westward extension.

But he said he was not interested in the party leader Charles Kennedy's job after speculation he might step down.

"I am not interested in his job and he's not standing for my job," he said.

Mr Kennedy has dismissed reports he might resign as "complete fiction".

Mr Hughes will take on Tory Steve Norris, the Greens' Darren Johnson and incumbent mayor Ken Livingstone on 10 June.

Other candidates include businessman Ivan Massow, who is running as an independent, and Ram Gidoomal for the Christian People's Alliance.

Mr Hughes said he wanted a "greater London, the most exciting place in Europe".

Rich and poor 'divided'

Tube trains would run until 0200 on Thursdays, Fridays and Saturdays under proposals outlined by the MP for North Southwark and Bermondsey.

And he set out plans for four police officers and four community support officers in each neighbourhood.

To increase vigilance against terrorism, he would create an emergency volunteer reserve and give out more details about what to do in the event of a chemical or biological attack.

"I want an easier, safer and more united London," said Mr Hughes.

"Mr Livingstone has been blind to the divides he and his government have created between the rich and poor and the inner and outer parts of London."

Other candidates are expected to launch their manifestos over the next few weeks.