Motorists will be slugged about $87,000 extra, each, in CityLink tolls over the next 25 years under the government’s West Gate Tunnel agreement with toll road giant Transurban, according to a new, independent analysis.

A Parliamentary Budget Office probe, commissioned by the Liberal Party, has revealed for the first time how much more CityLink motorists will be forced to pay as a result of the government’s contract with Transurban, which will allow Transurban to toll CityLink for 10 extra years.

A motorist using CityLink every weekday will have paid a total of $161,000 in tolls by 2044-45, the report released on Tuesday found.

An artist's impression of the proposed series of flyovers to be built as part of the West Gate Tunnel. Credit:Victorian government

This is $87,047 more than they would have paid if the government hadn’t entered a deal with Transurban to build the $6.7 billion West Gate Tunnel.