Tube fares in central London paid for with cash have risen to at least £3.
Travel with Oyster smartcards will be cheaper
A single Tube journey in zone one will now cost £3 instead of £2, while a single bus journey has gone up from £1.20 to £1.50.
Transport for London (TfL) said the new fares package is designed to encourage people to switch from paying in cash to using an Oyster pre-pay smartcard.
With an Oyster card, a zone one Tube ride will be cut from £1.70 to £1.50 - half the cash fare.
Mayor of London Ken Livingstone previously admitted the new single Tube fare of £3 would probably be the most expensive in the world, but stressed the package would halve cash journeys, making the Tube more efficient.
NEW FARES FOR 2006
Tube zone 1: £3 cash (£2 currently)
Tube zone 1: £1.50 Oyster (£1.70)
Tube zones 2-6: £3 cash (£2.10)
Tube zones 2-6: £1 Oyster (£1.80)
Bus (all zones): £1.50 cash (£1.20)
Bus (all zones): 80p Oyster (£1)
Brian Cooke, chairman of passenger group London TravelWatch, said people who used public transport infrequently were being penalised and some tourists may not want to or know how to buy an Oyster card.
Liberal Democrats also fear price hikes will clobber tourists and businesses while the Conservatives argue it will dissuade Londoners from leaving their cars at home.
The Forum of Private Business also objected to the new fares saying they would hit high street retail already suffering from a slump following the July bomb attacks and a rise in the congestion charge.
But Jay Walder, of TfL, said: "Nearly half of passengers who pay cash fares to travel on London's buses, Tubes, Docklands Light Railway and tram are on their way to work.
"By switching to Oyster these customers can really save on travel."
A further rise in fares is expected in 2007, the last of three previously announced price hikes.
The basic fare on London's buses rose by 20p to £1.20 in January last year.
From last August, all under-16s have been entitled to free travel on London's buses and trams and this will be extended to all under-18s in full-time education by September this year.