Frank Dobson is to launch an 11th hour bid to scare voters away from Ken Livingstone by plastering London with posters which will declare: "Beware the costs of Livingstone."

With just over a week until polling, Labour's candidate for mayor still believes he can swing Londoners away from Mr Livingstone if Labour issues dire warnings of how his "reckless" ideas would hit voters' pockets.

The posters will warn voters that Mr Livingstone's plans to levy congestion charges would cost motorists living in outer London £300 a month to drive into the capital.

Mr Dobson, who finally launched his manifesto yesterday, said: "Increasingly, Londoners are recognising that poking a stick at the government may not be a cost-free activity."

Labour has attempted to highlight the costs of Mr Livingstone's congestion charges. It claims Mr Livingstone would have to set up three zones around London, with motorists being charged more the closer they get to central London.

A motorist from Croydon, Labour claims, would have to pay £5 a day to enter the first zone, a further £5 once they cross the south circular, and another £5 to enter central London.

Mr Livingstone, who described Mr Dobson's campaign as "increasingly desperate", responded: "The claim that I would increase the tax burden by £300 a month does not have the slightest basis in any policy I have proposed. My manifesto clearly states that I would consult widely about the best possible congestion charge scheme."

Labour believes that scare stories about Mr Livingstone's independent campaign are paying off, with Labour supporters flocking back to Mr Dobson, particularly in the suburbs.

However, Labour has privately given up any hope of a Dobson victory and is fighting to ensure that Labour is not beaten into second place by the Tory candidate, Steve Norris.

Mr Dobson attempted to reach out to floating voters yesterday by pledging to rein in his spending plans to ensure that he would not be responsible for any increases in council taxes.

Mr Dobson also outlined populist measures, including plans to "name and shame" London's worst loan sharks. This could include placing posters of the most serious offenders throughout the capital.

Mr Dobson's manifesto rejects Tube privatisation, promises there will be no congestion charges and pledges to reverse the rise in the capital's street crime within two years by recruiting more police officers.

The manifesto: no tube sell-off and pledges to boost jobs

No tube privatisation, which Mr Dobson describes as "wrong in principle and wrong in practice". Day-to-day running and safety of the tube would be left in public hands. But Mr Dobson would turn to private companies to modernise the tube through an £8bn public-private partnership. He believes this is the best system because it would leave the private sector to carry the risks and would be £2.3bn cheaper than Ken Livingstone's bonds system.

No congestion charges in first term. Mr Dobson believes that it is better to improve the tube and buses before charging motorists to drive into London. He also wants to wait for a "proper electronic scheme" for congestion charging, which would take at least four years to introduce.

Creation of 100,000 new jobs by working with business to attract more inward investment. Mr Dobson would work closely with the businessman Sir John Egan, his choice to head the London development agency, which will have a £300m budget for economic regeneration. He would also set up a black and Asian skills taskforce to tackle the "scandal of ethnic minority unemployment".

Pressurise the government to increase the number of police officers, with a named officer for everyone. His deputy, Trevor Phillips, who is Mr Dobson's nominee to chair the new metropolitan police authority, would make the "battle against street crime" his top priority. The manifesto also echoes Mr Livingstone with a pledge to "root out corruption and racism within the police".

Name and shame London's loan sharks, who Mr Dobson describes as the "lowest of the low".

Limit spending to ensure the mayor is not responsible for an increase in council tax bills.