Last-ditch talks between London Underground bosses and the Rail Maritime and Transport Workers' (RMT) union on a pay and jobs dispute failed, RMT chief Bob Crow said, adding that the strike was expected to be "solidly supported."

Transport for London, which runs the capital's transport network, confirmed the strike was on but said extra bus and overground train services would be provided to help millions of commuters get to and from work.

The strike began at 7pm and will last until 7pm Thursday, although normal services were not likely to resume until Friday.

"We regret the disruption the strike will cause to passengers as the impact on Tube services is likely to be significant," Tfl chief Peter Hendy said.

"However, the mayor and TfL have prepared plans to keep London moving."

In addition to the extra services, Tfl said it would arrange for escorts to accompany people wishing to cycle to work, set up taxi-sharing facilities at major stations and lay on a free shuttle service down the Thames.

Crow blamed London Underground for the failure to reach a deal, saying that after hours of talks with mediators Acas on Tuesday, LU lawyers had "pulled the rug from under a workable agreement".

"The strike goes ahead and we expect it to be solidly supported," he said.

About 10 000 of the 13 400 people who work on the Tube are members of the RMT. They voted overwhelmingly for action last month in a dispute over pay, jobs and disciplinary issues, including the sacking of two drivers.

Earlier, London Mayor Boris Johnson had branded the strike a "ludicrous and unnecessary disruption".

"Londoners and commuters trying to do their level best to cope with the most challenging economic climate for a long time will be furious at this decision," he said.

The Football Association (FA) meanwhile has said that doors would open early for a planned World Cup qualifier between England and Andorra at Wembley Stadium on Wednesday to help fans getting to the match.

FA chief executive Ian Watmore said supporters who decide they will not be able to attend will be given a refund.

"We are disappointed this has happened. But we know English people love their football and will turn out in force I am sure," he said.

It is the first Tube-wide strike since June 2004, when RMT members walked out for 24 hours, although service on individual subway lines was disrupted in 2007 in a 24-hour strike by members of maintenance firm Metronet.