The chance for the public to have their say on plans to increase the congestion charge to £8 comes to an end on Monday.
The current congestion charge is £5
London mayor Ken Livingstone wants to raise the toll for entering central London by £3 for private cars. Commercial fleet vehicles would pay £7.
According to the mayor's office, the proposed rise would bring in an extra £50m to £60m per year and see traffic cut by a further 5%.
Mr Livingstone said the earliest the rise could be introduced is July.
The charge, introduced in February 2003, has been credited with reducing congestion in central London by 30% with 70,000 fewer vehicles entering the zone.
A rise in the charge from £5 to £8
A 15% reduction for those paying monthly or annually by giving annual payers 40 free days and monthly payers three days free
Amending the current fleet scheme by reducing the number of vehicles needed to participate from 25 to 10 and allowing cars to be counted as well as vans and lorries
A freeze in the late payment fee levied between 10pm and midnight at £10
Reducing the charge for registering a change of car
Increasing the number of petrol stations where the charge can be paid
Launching the consultation last November, Mr Livingstone said: "The congestion charge has been an unprecedented success in dramatically reducing congestion, pollution and accidents.
"We need to maintain and build upon this."
Mr Livingstone said the proposed increase would be accompanied by a raft of measures aimed at reducing the "hassle" of paying the charge.
But Angie Bray, from the London Assembly Conservatives, said: "This rise will be bad for business, bad for key workers such as teachers who have to enter the zone, and bad for all hardworking Londoners who already pay too much tax."
And the Liberal Democrats' Lynne Featherstone, chair of the London Assembly Transport Committee, said: "This price hike has nothing to do with reducing congestion but everything to do with raising a bob-or-two."