Sussex commuters travelling into London today faced chaos as a strike forced the complete shutdown of the Underground.

Massive queues built up at bus stations and taxi ranks as people tried to find other ways of getting to work.

Members of the Rail Maritime and Transport Union walked out at 8pm last night in a 24-hour stoppage over safety concerns.

Tubes were cancelled within minutes of the walkout and by 10pm yesterday the network was completely closed.

Services would normally run from 5.30am but at the height of the morning rush-hour Tube stations were closed and no trains were running.

There were chaotic scenes at bus stations and at some mainline railway stations as people tried frantically to find other forms of transport.

Economist Maurice Fitzpatrick of accountants Tenon said the strike would cost the London economy at least £60 million.

"The London economy is dependent on the Tube and the cost of a strike will clearly be significant.

"London will pay a high price as a result of the seeming inability of management and unions to agree to work together."

Bob Crow, general secretary of the RMT, joined a picket line at Leytonstone in east London and said he was delighted with the "solid support" for the strike.

Mr Crow, wearing a red baseball cap and an official picket armband said: "We are here today because London Underground has taken no notice of our safety concerns.

"They have paid lip service to what our members have to say."

Mr Crow apologised to members of the public for the disruption the strike was causing but claimed that most people supported the union's campaign.

Further strikes or other forms of industrial action have not been ruled out.

The union is concerned about the safety implications of the controversial public-private partnership of the Tube.