London's congestion charge has risen by more than 60% in a move condemned by businesses and motoring organisations.
Firms say the rise will affect business
The Forum of Private Business (FPB) has handed a petition against the rise from £5 to £8 per day for entering the city centre to the London Assembly.
It says the charge stops potential customers entering the zone.
But mayor Ken Livingstone says up to £45m raised from the hike will improve public transport and build on what the charge has achieved so far.
Fleet vehicles charges rose to £7 and those who pay monthly or annually get discounts.
'Easier to pay'
The road toll, introduced in February 2003, has been credited with reducing congestion in central London by 30% with 70,000 fewer vehicles entering the zone a day.
London mayor Ken Livingstone has said: "This will build on what has already been achieved in terms of extended bus provision, and in due course providing additional underground capacity.
"In addition, large discounts on monthly and annual payments will make the charge easier to pay for regular users and should lead to fewer penalty charge notices being incurred by drivers who forget to pay the charge."
Those paying on a monthly basis will get three charge-free days and those paying yearly will get 40 charge-free days.
Conservative Congestion Charge spokesman Angie Bray said the rise was a "serious blow" to city businesses.
'Damaging and retrograde'
"The revenue levels of the current charge have been so disappointing as it's a very expensive system to run," she said.
"This is a serious blow to many of London's businesses who are already in pain with the current charge level of £5.
"I suspect they are going to be in agony when it goes to £8."
Lynne Featherstone, Liberal Democrat London transport spokesperson, said: "Traffic levels in central London are still falling, yet our Labour mayor slams a 60% hike on congestion charges."
Dan Bridgett of the London Chamber of Commerce called the price rise "damaging and retrograde step which will appal the businesses of all sizes which are already being hammered by the charge".