The expansion of the ULEZ across Greater London is set to cost £200 million, Transport for London has revealed. 

The predicted cost is mainly set to fund hundreds of spy cameras to check that motorists are paying the £12.50 a day charge. 

READ MORE: ULEZ Expansion: See the full proposed expansion map

It comes as critics of the Mayor of London Sadiq Khan suggested that the money would be better spent elsewhere. 

The £200 million comes on top of the previous £130 million costs of the zones expansion last October from Central London to the inner boundary of North and South Circular roads where 750 cameras were placed. 

Harrow Times: London Traffic. (PA)London Traffic. (PA) (Image: PA)

Now Mayor Khan wants the expansion to be in place across all 33 boroughs by August 29 next year in hopes to reduce vehicle emissions in the suburbs. 

It comes as the TfL consultation on the plans currently takes place and will run until July 29. 

The new details of the predicted cost come following a freedom of information request according to the Evening Standard. 

TfL responded to the inquiry with: "Based on current assumptions made… the estimated costs to set up the expanded London-wide Ulez are in the range of circa £200m.

“This includes costs of signage, detection and enforcement infrastructure and systems, marketing, project overheads and risk.”

The sharing of the high cost is expected to create a lot of conversation and some backlash as many commuters face concerns of the new charge on top of the current cost of living crisis.