LONDON (Reuters) - London Mayor Ken Livingstone said on Monday that Boris Johnson is "remarkably dim" on public transport issues and warned voters not to trust his Tory rival to oversee huge infrastructure projects in the next decade.
Launching his transport manifesto ahead of elections in May, the mayor said failure to manage the work successfully would be a financial disaster for London.
It would lead to soaring budgets that would be met by higher fares for passengers and taxes on business, Livingstone added.
"We are on the verge of the biggest expansion in public transport since the era of Queen Victoria and the great age of railway construction," he told reporters.
"The most important role for the mayor in the coming years is to make sure that it is delivered successfully. The consequences of getting it wrong would be catastrophic."
London's transport network is due to be transformed by schemes such as Crossrail, an east-west rail link that will increase public transport capacity in the capital by a tenth.
Other projects include an inner London orbital rail link and the modernisation of Tube trains and stations.
Livingstone said Transport for London will invest 39 billion pounds in public transport over the next decade.
He accused Johnson's campaign team of underestimating the cost of one of their projects -- re-instating bus conductors -- by 100 million pounds a year.
"We can't have that sort of mistake repeated on the scale of the projects we're seeing before us now," the mayor said at a news conference in Stratford, near the 2012 Olympics site.
Tory proposals to change London's existing bus contracts while other cities around the country are trying to copy them were "remarkably dim", the mayor added.
Johnson shrugged off the criticism, accusing Livingstone of making "inflated promises" to save his job before the election.
He said: "This Labour Mayor says judge him on his record, claiming he is the man to deliver.
"Well, his administration has consistently fallen behind with major projects or gone way over budget, costing Londoners millions. What kind of record is that to be proud of?
"Londoners want a change in this city, yet Mayor Livingstone concentrates on looking after his friends and his pet projects rather than delivering the services that Londoners want."
A YouGov poll last month put Johnson ahead in the mayoral race on 44 percent, with Livingstone on 39 percent.
Full details about the candidates running in London elections on May 1 are at www.londonelects.org.uk
(Editing by Steve Addison)