Londoners would face a hike in Mayoral council tax to pay for Khan's experimental policies, according to new research revealed by Tory Mayoral candidate Zac Goldsmith.
According to the party, residents of the city would see a £175 hike in order to meet the promises made by the Labour Mayoral candidate regarding transport fares.
The Mayor’s share of council tax, which was cut by Boris, currently costs £295 a year for a typical Band D household.
Mr Goldsmith said: "London is just too important to be used as a four year experiment by Khan and Corbyn.
"Khan needs to front up to voters and explain which taxes he will raise, and which improvements he will cancel.
"I am standing up for Londoners who want to see better services delivered, rather than undermined by unworkable and reckless promises."
In January Mr Khan announced plans to freeze Tube fairs for four years, which he claimed would cost £450 million.
However, Transport for London estimated this would cost £1.9 billion to fulfill, around four times more than Mr Khan claimed.
When questioned by BBC London, he said: "TfL haven't said there is a £1.9 billion black hole."
A spokesperson clarified for Getwestlondon that "a four year fares freeze on Tube would reduce our income by £1.9 billion over the course of our Business Plan to 2020/21."
The BackZac campaign said this £1.9 billion hole would mean Mr Khan would have to either hitch up council taxes, cut public services, increase congestion charges or scrap regeneration projects across the city.
Mr Khan was approached for comment but did not provide a statement.
